Buy Vista now or wait for pci-e 2 cards? Crysis shows 20fps on pci-e 1

Just wondering what I should do. Atm I own a pretty fast PC (Q6600) with a Sapphire radeon x1950XT (bought at only 178 euro) that is running the demo Crysis at around the same performance the recent DX10 cards perform. When I compare DX10 with DX9 there are only a few scenes that really make some difference like fire for example. But here is my question. Should I buy Vista atm while the recent PCI-e 1.1 DX10 cards can't even play Crysis at a decent level like 60FPS? Or Should I wait till the next motherboards arrive supporting PCI-e 2.0 DX10 cards (5GHZ) and than start thinking about buying Vista later when it comes to gaming? Thx for the help....