Remember those IGP-less Core i5 CPUs we mentioned last month? They've now appeared on Intel's official price list (PDF). The chips come with their GPUs disabled and can be identified by the model numbers 2550K, 2450P, and 2380P. That first CPU features a fully unlocked upper multiplier, so it's the one you'll want.
Versus the existing Core i5-2500K, the 2550K offers 100MHz increases in base and Turbo frequencies, bringing the chip up to 3.4GHz with a 3.8GHz Turbo peak. Those speeds match the Core i7-2600K, which offers additional cache and Hyper-Threading support missing from the i5 series. Intel is selling the 2550K at $225—$92 less than the 2600K and a $9 premium over the 2500K.
The 2550K looks like a good match for Intel's P67 chipset, which doesn't tap into the Sandy Bridge IGP. That combo won't be able to take advantage of Intel's QuickSync video transcoding tech, though. Were I building a system today, I'd recommend sticking with the 2500K and pairing it with a Z68 motherboard to get QuickSync support. Intel seems intent on further segmenting its offerings, and the ones with the highest clock speeds may not always be the most desirable.