Wow you guys are a bunch of curmudgeons.
Maybe if you'd stop listening to crap you'd stop complaining about crap. Just like any other decade there was some really great music buried in a mountain of shit.
I think the decade will most be remembered for 3 things
1) the exhaustion of all the post- genres, post-rock, post-hardcore, post-metal, etc.
2) a full exploration of Eno's ambience heritage, best exemplified in the records put out by Type
3) the fusion/blurring of experimental pop and modern classical music