According to the file, the 3700-series of Ivy Bridge Core-i7 line up will replace the 2nd generation Sandy Bridge chips, sharing the same LGA 1155 socket. Each chip has four cores and eight threads, Turbo Boost by up to four steps and has 8MB of cache. However, the built-in graphics core is now the Intel HD 4000.
The top desktop model (six-core i7-3960X Extreme) will be clocked at 3.3GHz and will reach the 3.9GHz in Turbo mode. This one along with the rest three Extreme models will not feature built-in graphics cores.
Of course, there will also be quad-core i5 chips Ivy Bridge for desktops.
The Ivy Bridge chips for laptops will come in both quad and dual core versions, with bulit-in Inten HD 400 graphics and native clock speeds up to 3GHz.