I've playing with the nightly build of Songbird 0.6 pre today and am extremely impressed with how much faster it (finally) is with a large library on XP. And let me emphasize large library, as it exceeds 30k mp3s or the like.

Suddenly its running comparably with iTunes and WMP in XP and XULRunner plugins support the annoyances that iTunes lacks (a Now Playing list, anyone?!?). I realize that most of you reading are not first-adopters and would discourage you from testing the software, as it is still in early alpha status, but for my friends who are always playing with new software, please check it out.