295 is a good card but you are better off with newer tech that will run cooler and use less power. 295 may feel like a bad decision if they start releasing a bunch of pure DX11 titles. even if it takes a year to see a dozen DX11 games, i think it is the wiser purchase. you will be able to grab a second one once Nvidia releases their new product for a great deal as ATI seems to have a nack for lowering prices when competition shows up.
Its newer tech (40nm, dx11, eyefinity), it runs cooler and uses less power than the GTX 295. The GTX 295 is marginally faster in some games and in other games that dont scale well with SLI it performs worse.