Has anyone played Rock Band 3 yet or is GH2 still the best music game evar?
Been playing it since launch; I don't have any of the "pro" instruments yet so I'm still mostly just using the dinky plastic guitar.
It has a few options the series really should have had a long time ago, such as the ability to rate songs and sort them by rating, the ability for players to quickly change their individual settings, various features for sorting your playlists... It also has more of a cohesive, characterful playlist than RB2's, which was kind of messy and filled with ridiculously bad metal songs. That said, there are less highlights for me than either of the previous games.
There are quite a few stupid oversights though. They claimed before launch that you would be able to filter who you'd play with online by how much DLC you have in common - there is in fact no way to do this. The automated matchmaking does seem better, but you're still very likely to be stuck with a few pillocks who only have the basic song list.
They haven't added pro, vocal harmony or keyboard tracks to any existing DLC songs, and you have to actually
pay extra for new DLC with pro guitar. That's pretty outrageous given how expensive the peripheral is. And if you bought a keyboard, for now you're stuck with Rock Band 3, The Doors and the Bee Gees.
It seems like you fail out of songs much quicker if you're having a hard time. You also don't get ranked on the leaderboards if you have No Fail Mode on - I had it on as a leftover from Ocean Size's insane solo, then played Mountain Song on bass and came in #1 in the world, but it wasn't recorded. I was angry.
Seems like a trivial thing, but the character customisation is annoying. There's a complex face generation system in addition to the usual stuff, but if you don't like your work once you've finished (which is very likely, as you only get a couple of angles during the creation process, and the finished characters have some very unpleasant animations), you can't edit them, so you have to delete them and start over again.
Also, you no longer have to "buy" clothes from song winnings (instead of winnings you just get fans, which improves your e-penis rank. But the final rank requires you to get every single goal for every single instrument in the game...), you just unlock new stuff as you achieve goals. This means that every time you want to change your outfit, you have to go sifting through the entire menagerie of trash to find anything you'd actually like. There's no way of saving your favourite outfits. Like I said, trivial, but annoying. It's also much harder than before to create a good-looking character.
There are a lot of other small ways in which it feels clunky. It's been two years since Rock Band 2, I really felt they should have done a lot more. If you're new to the series, you're not missing much if you pick up cheap copies of RB2 and RB1 (the latter for the playlist, which can be imported).
Sins of a Solar empire has a similar community, unfortunately. Hopefully that's not the case with all Stardock games. 
