I think gears 2 should have a matchmaking system like halo then you could choose like 2v2 or 4v4 or even 8v8.

Longer story mode with 4 player co-op.

NO ACTIVE RELOADS!!! especially for the sniper.

Add more mp game types deathmatch, ctf, etc

Lower host advantage as much as possible.

I would love to have a knife in mp and maybe some C4 or something.