So, what's really new? What's new is just more of the same and that's made things much easier. To me, getting sound to work at all was a big kick just a year ago. I'd read that other people had been making sound work under Linux for years and that commercial embedded systems were everywhere. The number of free drivers has steadily increased and auto configuration utilities have benefited and matured. The big change is that newbies can now enjoy sound playback and recording under Linux without too much effort even in the "hard" distros.
Knoppix is the most dramatic demonstration of this new ease of use. As of version 3.3, a newer and vastly improved system of drivers called the Advanced Linux Sound Architecture, has been stable. 2.6 kernels were supposed to use ALSA by default. Mepis and dozens of other live CDs work much the same way.