A fella in the US has got his hands on a reference GTX 660 Ti from BestBuy and posted a couple of vids.
First, the unboxing:
And secondly, benchmarks for BF3, WOW, 3DMark11 and Unigine 3.0.
Looks good. Basically what we've seen before with performance pretty close to the GTX 670 at 1080p.