The Animal Collective is an awesome band. They are pushing an envelope that isn't too well represented in the mainstream, and its moving music forward in ways that we can't see now. Thats not to say they're the best at what they're doing, or that they are the musical identity of our generation, or that they have the best album of 2009. They are simply good musicians, doing something you don't see too often.
As for everyone ripping on electronic music, it is just as much purist music as floyd, hendrix, or whoever else you have in mind. The challenge behind electronic music is making all the sounds, tracks, melodies, harmonies, and lyrics come together, a wonderful example of which is royksopp's most recent album. It takes real musical knowledge and instrumental skill to create this stuff, which is something I doubt a lot of people in here have (no offense, that doesn't mean that you don't know music). It is music, just a different type more based on audio production than actual rehearsal, which does NOT mean it is music any less than anything else.
The musical identity of our generation? Impossible to determine, only time will tell.