Ok, here i will list the features we're missing, and i'll try to complete SOME of the missing graphics and concepts for the features i can help at. Some of them should be made by the theme owners.

Missing Graphics:
1.Vocals, to make kind of similar images to GH3 graphics.
2.Bandstarmult, i think the new Guitar Heros have it.
Missing Features:
Can't think of one now.

Missing Graphics:
1.The Real Lobby
2.Bandstarmult probably
3.Vocals, and a concept how they'll be done.
Missing Features:
1.Beginner mode
2.Hmm, "Hot Start?"
3.Slap bass notes. FoFiX issue 255
4.Overlaping sustains FoFiX issue 254
5.Battle mode.

Missing Graphics:
1.Tug of War [Done]
Missing Features:
1. Tug of war.
2.HO/PO system. FoFiX issue 280
3.Setlist creation.

Missing Graphics:
It's early to mention them now. Sometimes later when game is out maybe.
Missing Features:
1.Party Play Mode...
2.RockFest Mode... [Contains more multiplayer modeds..]
2.1. Momentum Mode
2.2. Elimination Mode
2.3. Perfectionist Mode
2.4. Do-Or-Die Mode
2.5. Streakers Mode
3.Band Moments..
4.Band Revival meter..


Missing Graphics:
1.Vocals, to make kind of similar images to GH3 graphics.
2.Bandstarmult, i think the new Guitar Heros have it.
Missing Features:
Can't think of one now.

Missing Graphics:
1.The Real Lobby
2.Bandstarmult probably
3.Vocals, and a concept how they'll be done.
Missing Features:
1.Beginner mode
2.Hmm, "Hot Start?"
3.Slap bass notes. FoFiX issue 255
4.Overlaping sustains FoFiX issue 254
5.Battle mode.

Missing Graphics:
1.Tug of War [Done]
Missing Features:
1. Tug of war.
2.HO/PO system. FoFiX issue 280
3.Setlist creation.

Missing Graphics:
It's early to mention them now. Sometimes later when game is out maybe.
Missing Features:
1.Party Play Mode...
2.RockFest Mode... [Contains more multiplayer modeds..]
2.1. Momentum Mode
2.2. Elimination Mode
2.3. Perfectionist Mode
2.4. Do-Or-Die Mode
2.5. Streakers Mode
3.Band Moments..
4.Band Revival meter..