hmmm, let's see, 1. crysis, 2. video editing, 3. prefers nvidia, 4. no concern with power draw.
let's hit those one at a time:
1. crysis is slightly better on a gtx 295. However, in the next 3 years it is highly likely that 5870 will meet and/or surpass gtx 295 because amd will spend lots of time and money optimizing its drivers and nvidia will NOT spend much more time at all on 295 as soon as gt300 gets here.
2. "some" video editing will not see enough of a boost from a gtx 295 to a 5870 to be relevant most likely. If he was doing "a lot" of video editing and we could assume that over the next 3 years the gtx 295 would continue to outperform 5870 in this area it would be different, but we simply don't know about that and this seems to be a small part of the op's requirements.
3. there is nothing that the OP has said or done to indicate a preference for green or red, if you look at what he's written he appears to have just assumed (as most people do) that nvidia has the fastest cards for gaming.
4. I did not see the OP post anywhere that he had no concern for power draw. In fact, how much money will he save over 3 years with a power sipping 5870 vs a gtx 295? $100? more? As a conservative estimate lets say that the 5870 will draw 50w less power under all conditions. that equates to 36kw/month. again lest assume a low power charge of 10 cents per kW*h, so $3.60 per month. that's about $45 per year, so closer to $135 over a 3 year period with conservative estimates.
oops: forgot to mention another significant advantage: no dual gpu headaches, OR the ability to live with the dual gpu headaches and get much better performance.