asic vs fpga comparison issues

Hi

How do i compare asic power/timing features for the same design with an FPGA having that same design....i mean what tecnology does xilinx use to fabricate their die ,

The Xpower readings from the ISE foundation gives an estimate of power , but i would like to know with which asic flow is this power comparable ultimately leading to a hybrid chip ( if it was possible)

thanks Paraag