How much more powerful will Ivy Bridge be compared to Sandy Bridge?
Intel Estimated Ivy Bridge will be 20% more powerful than Sandy Bridge - Source
When will Ivy Bridge Launch?
There have been no exact dates given by Intel but articles have indicated the launch will be in the second half of 2011 or early 2012 (So you will get you chip before the world ends!).
Will Ivy Bridge Support PCI Express 3.0?
Yes.
How many EUs will Ivy Bridge have?
With its 22nm architecture Ivy Bridge is aiming even higher and new rumors says that beside support for DirectX 11 it will increase the number of execution units from 12 to 16 with Ivy Bridge. With a new and more efficient process the clock frequencies will go up compared to Sandy Bridge but considering the base architecture is the same Ivy Bridge will get 25% better overall performacne thanks to the extra execution units.