I'm going to grab the Disturbed songs because they are cheap.
I like the German songs and the Muse song is awwweeeesome.
While I don't need RB2, I hope EA/HMX/MTV announces it and somehow punches GH4 in the gut. If they do song creation and backwards compatibility with RB1 songs, I'll honestly have no reason to bother with GH4.
Holy crap, I just youtubed some of the Jimmy Buffett stuff and wow... I wonder how the Rock Band crowd will take it.