For the first round of releases the Sandy Bridge CPU will be 32nm and fit into the 1155 socket (yes, a new socket) on the desktop. Each of these (including the Core i7 variants) will have an integrated graphics processor capable of running at up to 1350MHz (when needed, and using a form of Turbo Technology). Due to a linking of all the parts in the CPU, the BCLK will be locked to 100MHz, but there will be certain “K” variants that will allow you to overclock by changing the multiplier.
The PCIe lanes will still be on the CPU with Sandy Bridge, but will also be a limiting factor for board design. Again, talking with a few OEMs I have been told that developing for Sandy Bridge is “challenging” and that due to certain limitations of the chipset, companies are having to work hard to add in the same features they are used to using. These are items like TurboV, OCGenie, OCDNA, Easy Boost and others that motherboard manufacturers have been using to overclock the current generation of CPUs. They will need to be reworked both on the software and the BIOS sides to ensure that they work properly. Read more at TweakTown.