Yup, the multiplier should be 8x. You should be able to turn off Speed Step in your BIOS, and something else called C1E if you built your rig. From what I've heard, Speed step reduces your voltage, and C1E reduces the CPU's clock speed. Then you will see the full 2.66ghz. Voltage can be between 0.962V-1.350V (recommended settings).
If you plan to OC it should do well. For some reason I can't get my E6750 above 3.11ghz, but I'm not sure if it's because of the processor or the motherboard (Gigabyte P35-DS3R)... And that's pretty low compared to what I've read.
Good Luck!