I don't think FPGA's had the same effect on BTC as ASIC's will. 

If my understanding is correct, a few of the advantages FPGA's had over GPU mining is that they consume less power and that you could host more devices than a traditional GPU rig, which could only host 4-5 cards (typically).  ASIC's big advantage is that they consume even less power than FPGA's and the devices  typically have smaller footprint (ie.  Avalon's 85 Gh/s rig vs a horde of FPGA's on racks). 

I'm extremely curious to see how the network hashrate will be over the next several months.  It's only been two months since I started reading into bitcoins and the total network hashrate has doubled as well as the difficulty.  I can't seem to help but wonder what all this computing power can be used for other than mining bitcoins...the amount of computing power is staggering.