Despite there being delays in place for Intel to feel comfortable releasing its next generation mainstream platform to market, HKEPC has managed to gain quite a bit of info about Intel's supporting 5-series chipsets. It seems the lineup is a little more complex than first thought, with there being no less than five different models across the lineup.
These models include the P57, Q57, H57, P55 and H55. With the exception of P55 and P57 which rely on discreet graphics support, these are all built primarily for LGA1160 processors with built-in GPUs, supporting Intel's FDI (Flexible Display Interface). The Q57 is aimed more so at the business / enterprise level with support for several exclusive technologies to help make the system better equipped and easier to manage in workstation environments.
As for learning about the actual differences between them all, it's quite a feat to grasp, especially as the source is Chinese. But the lads at Techpowerup have managed to decipher much of it and give the full rundown here.