I´ve seen many posts of people who shows their current or next i7 configuation and they put the i7 920 or 940 processor with memories of different manufacturers with speeds between 1333 and 1600. But in the "system builder" of the web page where i´m going to buy the PC shows an error that says something like "the CPU you have chosen only suports memories DDR3 800 to 1066 Mhz"
The intel specific specs will say 1066MHz memory. However the 1333,1600,1800,1866 memory you buy is essentially "overclocked" memory. DDR3 has a built in XMP profile that will set all of the clock speeds for you in the BIOS as well as voltages. The memory's stock speed is 1066, just like a CPU it can be overclocked. And memory companies rate their memory for certain speeds with certain timing. If it says DDR3 1600 8-8-8-21 at 1.6v it should run just that.
I'm pretty sure that the difference between DDR3 1066 and, say, DDR3 1333 or 1600 would be neglegible in all real life scenarios, the most noticeable upgrades have always been GPU, CPU and RAM size, but not RAM speeds
But yes, you can run RAM fater than 1066 with an i7
Oh, forgot to add, if I'm wrong plz someone correct me