How many people commenting actually OWN and USE both?
I do - got a couple of each but the Macs are getting on now. As a developer I'm constantly testing on both, and when stuff fails purely on one platform it's very useful to be able to debug on that platform instead of stabbing blindly on the other.
However, as the Macs need replacing now I don't think I'll bother getting new Mac hardware - if the media industry is insistent that "they use Macs" then really it's OSX they use, and I'll just hack Tiger or something on to some new PC hardware to save some cash.
I will always be PC-based for primary development.