I think this is a lawsuit of convince. Konami may be in the right, or they may be in the wrong. I don't care...I hate lawsuits.
But to me, if Konami wanted to make an issue out of this they should have started by suing when the very first Guitar Hero game came out...or at least when the very first Rock Band came out.
Since it comes on the heals of Konami entering the arena of Home Market Band games, where 2 is already a crowd and 3 is insane...it just seems like too much.
It makes me wonder what Konami's real goal is. Perhaps it is a desire to get Rock Band's instruments to work with their game...a sort of backwards compatibility issue...without having to pay royalties for it. That would explain why Konami is going after Rock Band and not Guitar Hero...because it is the first on the market and the industry leader at this point.