There are apparently already a thing (Xeon processors with FPGAs seem to have come out a while ago).
Xeon processors with FPGAs have been announced over a year ago [1] (June 2014) and we haven't heard any details or exact dates since then.
[1] http://www.extremetech.com/extreme/184828-intel-unveils-new-...
Personally, I would love to see a day when FPGA coprocessors are a thing, and FPGA companies are big enough to make it happen.