My husband picked up Rock Band 3 the other day. Unfortunately, I haven't had time to play it much. Not to mention that I've had some throat wackiness for the past week, which makes it very difficult to sing. However, I did manage to croak through a few songs Tuesday night. The character creation is OK, but a lot of the default faces are just plain ugly. You need to do a bit of tweaking on the cheeks and jawline to get any sort of prettiness out of them. (At least for the girls. I didn't try to create a male character.) After you finish making your character, each player gets to make their own band. This gives each individual player goals to reach with their band. It also means that each player gets their own rewards. Instead of needing money to purchase upgrades, you win them by playing various gigs. You also get to pick the "stand in" computer players for your band, if you don't have anyone to play with you. (My husband's favorite is Moosejaw - the homeless man that needs to put down the guitar and find some construction employment or something.) I think this makes the whole band experience a lot better.
I've only played the vocals so far. In my opinion, the vocals have gotten a lot better since RB2. I believe they have keyed some of the songs up a bit so they aren't really low anymore. This is awesome for me because I always have problems hitting the very very low notes. (Yes, you can sing an octave up but that sounds wrong.) They've also changed the way spoken words are handled. Well, it's not a huge change. Mostly a visual one. Instead of "notes" to speak, it just shadows that whole section to give you more time to hit the beat.
My husband picked up the keytar yesterday. I plan on finding some time to play around with that so you'll definitely hear more about the new Rock Band in the future!