Apple’s “Let’s Rock” event today was like going to see The Rolling Stones or The Who in concert. Mick and Pete can still rock, but not like they used to.

Apple’s line of iPod products still rock, but not like they used to. Apple unveiled an updated second generation iPod Touch, yet another iPod Nano form factor in snazzy colors, a 120 GB iPod Classic, and new headphones. That was it for hardware.

On the software-and-service side, iTunes 8 was introduced. The iPod Touch and the iPhone are getting a 2.1 software update, due Friday. The iTunes Store will be selling high-definition TV shows for $2.99 a pop. And estranged NBC Universal is putting its shows back on iTunes after a hiatus of nearly a year.

As Philip Elmer-DeWitt noticed for Fortune, “Apple fails to wow Wall Street” and saw its shares fall more than 7.5 points, or 4.7 percent, during the event. The stock closed at 151.68, down nearly four percent for the day.

Frederic Lardinois of ReadWriteWeb simply said “Let’s Rock” was “a bit of a lackluster event.”

Agreed. Apple’s announcements today were incremental and more maturation of a product line and ecosystem than game-changing, earth-shattering, stand-in-line-for, can’t-live-without, and must-have gadgets since, well, the first iPod or iPhone.

Here’s a roundup of “Let’s Rock.”

Second-generation iPod Touch

The most significant changes to the iPod Touch is the inclusion of a volume rocker switch, so you don’t have to raise or lower the volume through the touch-screen interface, and a built-in speaker.

Everything else is cosmetic. The Touch is thinner and its look has been updated to be more like Apple’s new signature product, the iPhone 3G. The Touch’s rounded chrome-steel backing wraps around the back and sides of the device like the iPhone 3G, which has a hard plastic back to improve cellular communications.

The Touch does have an improved battery — 36 hours of music (up from 22) and six hours of video (unchanged), but we’ll see. Apple’s battery estimates tend to be best-case, which isn’t always the case.

The Touch also is Nike+ enabled for the fitness conscientious among us, and it will be getting a software update to allow for the on-device Genius playlist, Microsoft Exchange push email, a multi-language keyboard and dictionary support, and MobileMe multiple calendar and contacts support.

The other significant change for the iPod Touch is price. The 8 GB model is now $229 (down from $299), the 16 GB model is $299 ($399), and the 32 GB model is $399 ($499).

The latest Nano

Seeing the new Nano makes us think that the short, squat third gen Nano was simply a stepping stone to get Apple from second gen to fourth gen, from no video to video.

The new Nano is Apple’s thinnest design ever — not that any previous Nano, with the exception of maybe the first one, was too thick. It sports the same two-inch high resolution display, but its glass is rounded and provides a more pleasant viewing experience. The Nano plays back video in portrait and landscape modes, and the inclusion of an accelerometer switches between orientations.

The Nano now comes in a Sherwin-Williams pallet of colors — silver, gunmetal, purple, blue, green, yellow, orange, red, and pink. Fun, but hardly essential, unless you need a red Nano to go with your shoes and silver or gunmetal to wear with any outfit.

The Nano also gets a software bump. The new intelligent playlist, dubbed “Genius,” will take a song and generate 25 songs that share similar characteristics. It’s sort of Pandora-like behavior that will work for some and be completely ignored by others.

For photos of the new Nano, taken from every conceivable angle, check out the usual great coverage from Engadget (hands-on) and Gizmodo (photos and first impressions, review).

iTunes 8

The “wow” factor in iTunes 8 is reminiscent of services from social music sites such as Pandora and Last.fm. The new Genius feature examines music in your library and makes recommendations for songs you might want to buy at the iTunes Store.

“It basically validates what we’ve been doing,” Last.fm cofounder Martin Stiksel told Wired. “But we base our recommendations on everything you listen to — not just Apple products — and we don’t just do it for an e-commerce end, we connect users to their music soulmates and give concert recommendations too.”

“Genius” is a fancier version of the recommendation engine found when you visit the iTunes Store, which suggests songs and artists you might like based on past purchases. If you opt-in, the service sends your library and usage data to Apple anonymously, but there’s no indication if just Apple purchases are transmitted or the MP3s you ripped off a friend’s CD is sent as well.

A couple of other interface changes include a “grid view,” enhanced accessibility, and a new visualizer.

NBC’s return to iTunes

NBC Universal and Apple ended a nine-month feud when Jobs announced that programming from NBC’s networks will be returning to the iTunes Store. Michael Learmonth of Silicon Alley Insider asks, “Who blinked?”

NBC’s president and CEO Jeff Zuker says it was Jobs, and Jobs says it was simply two companies putting aside their differences to do business. Zucker contends he got what he wanted when NBC split from iTunes last fall: variable pricing.

But a closer look reveals that Zucker got three price points, but not exactly the variable pricing he was shooting for months ago. Standard programs remain unchanged at $1.99 each. High-definition TV programs will be $2.99 — something that Home Box Office initiated in May, so it’s not new. Apple will create a 99-cents price point for back-catalog shows such as “The A-Team” and “Miami Vice.”

Pricing aside, what matters is that NBC U shows like “The Office,” “Monk,” “Heroes,” “30 Rock,” “Eureka,” and others should be back in the iTunes Store shortly.

New headphones

The 4G Nano, 2G iPod Touch, and the revised 120 GB iPod classic all support audio recording, but to do so you must purchase a new headphone that includes an integrated mic, allowing the devices to record without bulky attachments.

The standard headphones with a mic will cost $29. A premium pair with independent woofer and tweeter drivers will cost $79.

Apple by the numbers

A few Apple, iPod, iTunes notes from “Let’s Rock.”

• more than 65 million people have created accounts in the iTunes Store
• Apple is the No. 1 distributor of music, ahead of Wal-Mart and Best Buy
• content now includes 8.5 million songs, 125,000 podcasts, 30,000 TV episodes, and 2,600 movies
• customers have downloaded 100 millions applications from the App store
• more than 3,000 apps are available at the store, including 700 games
• 90 percent of the apps are priced less than $10, with 600 offered for free
• the iPod holds 73.4 percent of the U.S. digital media player market
• 160 million iPods have been sold to date
• more than 5,000 add-ons have been brought to market to support the iPod ecosystem

Conclusion: What’s next?

It’s too early to say that Apple’s Commander in Chief, Steve Jobs, has lost his golden touch.

After all, he was responsible for iPod 1, iPod 2, iPod on the Mac and PC, iPod Photo, iPod with Video, iPod Mini, iPod Shuffle, iPod Nano, the iPhone (with iPod functionality), the iPod Touch, iTunes desktop music-management software, the iTunes Music Store, iPods with wi-fi for over-the-air music downloading, the inclusion of TV and movies for rent and purchase from the iTunes Store and, let’s face it, AppleTV 1.0 and 2.0.

Nearly all of those were innovative product launches that changed popular culture. So what if the “Let’s Rock” products are only incremental improvements. Let’s see what Jobs has planned next.

Apple