With the death of copyright-protected digital music imminent, several questions come to mind. Chief among them: What’s next for iTunes? And does anybody want to pay for music anymore?

As last100 reported earlier today (via BusinessWeek), Sony BMG is set to become the last of the four major record labels to at least, in part, scrap digital rights management, or DRM. Sony BMG now joins rivals EMI, Universal Music Group, and Warner in offering some of their catalogue DRM-free, meaning consumers can play the purchased music on any MP3-enabled device.

Already the Web is cheering: Ding Dong the Music DRM Witch is Dead! And RIP DRM. But, truth be told, DRM ain’t dead yet. Sony BMG and UMG are in an experimental stage, with results to be reviewed.

Even though DRM isn’t completely dead, the prediction of its demise in 2008 is still a good one. It’s coming. The questions are when and in what form.

According to BusinessWeek, Sony BMG is set to become the last of the four major record labels to, at least in part, ditch DRM. Motivated by the emergence of a genuine competitor to Apple’s iTunes – the Amazon MP3 store – Sony BMG will join rivals EMI, UMG and Warner to offer tracks unencumbered by copy-protection software.

Coming out of a holiday stupor, I see there’s some good news and bad news about the music industry in recent days.

The good news is that the Warner Music Group is offering its complete catalog DRM-free through Amazon’s MP3 store. Some of Warner’s artists include Led Zeppelin, Aretha Franklin, and Sean Paul. (last100 music year in review.)

The good news is that Warner is now the third of the Big Four record labels to sell music DRM-free. EMI and Universal Music Group offer their catalogs to Amazon MP3, but only EMI also sells on Apple’s iTunes. The lone holdout among the majors is Sony BMG.

The bad news, at least for Apple, is that Warner has not said anything about offering its music DRM-free through other digital stores as iTunes. And now there are two labels out there — the other being Universal — that’s attempting to make life tough for Apple, seen by many to have too much power over the digital music industry.

It’s been almost two months since we reported that Apple is opening up iTunes for movie rentals. Today, if reports are true, we finally have good news that Apple and News Corp. have signed a deal that will allow consumers to rent the latest 20th Century Fox DVD releases by downloading a copy from iTunes.

One frustrating aspect of the Radiohead pay-what-you-want experiment is the lack of definitive numbers — yet. ComScore says this, Radiohead says that, the record industry says this, the artists say that.

The Radiohead experiment is now old news, but that doesn’t mean others will not attempt their own experiments. Following in the footsteps of Radiohead, Steve Hofstetter, an up and coming comedian with a strong Internet following among high school and college-age kids, has released his latest album “The Dark Side of the Room” on his Website. He’s believed to be the first comedian to take a pay-what-you-want approach.

Hofstetter’s last CD, “Cure For the Cable Guy”, reached No. 20 on the Billboard comedy charts, and he’s performed on VH1, Showtime, ESPN, and others, as well as his work being available at his Website and on YouTube. He’s extremely popular on MySpace and Facebook with hundreds of thousands of friends.

Hofstetter is no Radiohead, mind you, but it’s interesting to see all sorts of known, somewhat-known, and unknown artists experiment with the pay-what-you-want model.  What’s nice is that Hofstetter has provided real numbers:

Radiohead’s grand “In Rainbows” experiment ended this week. Whether it has been a success, only Radiohead and its management knows. Everybody else can argue about it.

But one thing is for certain: Radiohead put in motion, as The New York Times notes, “the most audacious experiment in years.”

Radiohead is no longer selling the album as a download from the Web site inrainbows.com.

“It’s been the most positive thing we’ve done,” Radiohead’s frontman Thom Yorke said. “We hope you shared the experience with others.”

Walter S. Mossberg, The Wall Street Journal technology reporter known by many as Uncle Walt, got his hands and ears on a prototype of the once-again-delayed Slacker Personal Radio. His verdict: buggy.

Bugginess is a part of any Version 1 product release, and the bugs explain why the Slacker portable player — due this month — has been moved back to a January 31 release date. (Slacker info.)

Mossberg describes the player as “chunky, black plastic” and “dominated” by a four-inch color screen. It provides a rich listening experience: the sound is good, the Wi-Fi connection worked in both Walt’s home and office, and included were album art, other photos, artist bios, and album reviews.

These were overshadowed by the bugs detailed in Walt’s review. “The two prototype Slacker units I tried, however, were hobbled by bugs and glitches that the company must expunge by the release date.” Mossberg notes that Slacker is aware of the glitches and is working to fix them.

What caught my eye  — over and above the bugginess — was how Mossberg characterized Slacker’s positioning of the product. He notes that 100 million music fans know the joys of owning portable digital music players, but to get the most out of these products he says takes too much effort or money for some people.