IGN has posted the full achievement list of Rock Band 2 which is due next month.
- Solid Gold, Baby! – Gold star any song. – 25
- Flawless Fretwork – 100% a song on Expert guitar. – 25
- Flawless Drumming – 100% a song on Expert drums. – 25
- Flawless Singing – 100% a song on Expert vocals. – 25
- Flawless Groove – 100% a song on Expert bass only using up-strums. – 25
- Flawless Guitar Solo – 100% a guitar solo using only the solo buttons. – 20
- Flawless Guitar Solo – 100% a guitar solo using only the solo buttons. – 20
See the full list here http://xbox360.ign.com/articles/897/897508p1.html