It is funny people keep pointing at these mythical FPGAs lol.
I'm sure they will exist eventually but I don't think they are good enough yet.
The high net hash is most likely due to rented rigs and/or miners who want to try to mine X11 for the first time. All the pools were "attacked" by massive influx of people using scrypt protocol.
SummerCoin could possibly be the coin to push X11 algorithm to mainstream crypto (and of course, the arrival of better FPGA).
In the mean time, the increase of hashrate is not attributed to FPGAs.... yet......
Actually You can use the ztex boards just fine for X11, there is already a public bitstream for Blake, which is a part of X11, someone just needs to modify this to work with the Rest of the algos