x86 isnt going away in the nearest future, but the top is a cold and lonely place, and others are compeeting for the top.
But going for x86 now, would IMHO be a wrong move, especially since ARM is now moving forward, plus PPC is far from gone.
If there were to be a move to an other architecture, such a decision has to be based on extensive research and good foresight.
So personally I think, that sticking to PPC for NG would be a good move, and as for classic, then FPGA would be the right choice.