It is NOT acceptable to have to buy a new graphic card every year. PC life cycle is 3 years, and games should run fine on all these configurations.
I also understand that hardcore gamers or brand new PC buyers should have better and excellent graphic performance and quality, but the game should still be playable (without being completely ugly) on other PCs.
I was already disappointed last year with spec requirements for GRAW. Now I hope for a performance patch for ArmA or I won't buy the 3 licenses of French version in 2007 for my family and me.
And more, if I buy a 7900GS 256MB now, I'm sure that GRAW2, Crysis or another game will be unplayable or ugly in 2007 for multiple reasons: need 512Mb of graphic memory, DirectX 10, etc... I don't even think about 2008 games... unacceptable !