Just bought a 600g WD Velociraptor (SATA 6GB/s) & would also like to take advantage of USB 3.
I currently have an i7 920 on an EVGA X58 board.
Should I get another 1366 motherboard with the newer stuff on it? Or is 1366 a dying breed?
Would I be better getting a new 1156 board and a new CPU & selling what I have?
Your Velociraptor will perform just fine on your current motherboard. Most of the time, data will be transferred at mechanical speeds off of the drive platters. On occasion, the data will be found in the cache, where the 6gb rate might be possible, but the time is so minimal that you will not be able to tell the difference from 3gb.
USB3 is good, particularly if you will have a USB3 device like an external drive for backup. Whenever that time comes, just get a USB3 add-in card which will be much cheaper than replacing a motherboard.
When Sandy bridge arrives, it will require a new chipset and motherboard. For mainstream processors, that will be socket 1155, and for enthusiast and high end sustems, it will be socket 2011.
Your 920 will be good until it won'r run your apps or games well. Keep it until that changes or you get the itch for the new stuff.