Check out this plot (also on our stats page). We see that over time, FAH has added about 40,000 active processors each year since FAH was released (in October 2000).
This graph doesn't talk about FLOPS, which have gone up dramatically faster, due to the advanced clients in FAH (SMP, PS3, and GPU clients). The FLOPS has gone up much faster, and we expect it to grow even more.
Note that these are *active* CPU's, not total "devices" or anything like that. Many projects like to list the total number of machines that have ever run the software (even briefly), whereas the numbers here are very different -- they are the number of machines which have recently returned results (and are thus "active").
We look forward to continuing growth in FAH, as we try to make FAH better and better than before.