If it's ultra-fast memory you're looking for, the G.Skill booth at CeBIT 2012 should be your first destination.
This year, the extreme memory manufacturer is exhibiting a 16GB quad-channel RipjawsZ kit that runs at a cool 2,666MHz.
The 16GB kit (4x4GB) operates at 1.65V with loosened timings of 10-12-12-31 and was shown running on an equally-high-end ASUS's Rampage IV Extreme motherboard equipped with an Intel Core i7-3960X processor.
Not one to beat around the bush, G.Skill claims that this brand of RipjawsZ is "without a doubt the best quad channel memory solution on the market." The 16GB kit will no doubt fetch a healthy premium when it arrives at retail, and while it's about as good as it gets on X79, it'll be interesting to see what speeds G.Skill will reach on Z77.