They trade benchmarks. Each has games in which it performs better. You might be able to declare the 6950 "better" based on an fps average, but it'll be very close, and I generally consider it a tie.
You can wait as long as you want in the tech world. There will always be new stuff just around the corner if you look far enough away. If a month doesn't seem like a lot to you, then by all means wait. If you want performance now, though, I'd take that Ti or this 6950
. 1gb is enough, assuming you're playing on a resolution of 1920x1080 or lower.
Actually, you've put up a bad comparison. Your 6950 is in $CAD, but the Ti is in $USD, so their price difference is increased. The harder question is between my two 1gb cards, above. I'd probably take the Nvidia, but then I've got a 460 running, so I'm biased. It's hard to say; the two are very similar in performance.