It isn't illegal. The EULA has not stood up in court as being legally binding yet anyway. Why would I want to save up my money to buy a Mac Pro when they're currently insanely overpriced? The hardware in the 2.66GHz Quad Mac Pro is about $1000 overpriced (Dell sells virtually the same machine for $1389). I could not buy a Mac Pro with the same performance as what I've built down no matter how much I paid. The only thing I'm going without now compared to the W3xxx processor based workstations is ECC memory support, which frankly, I can live quite happily without.
Why would I need to suggest to clients that I am a Mac owner? What kind of a fool gets work based on what their computers look like?
Use linux then... buy a G5... ya know?.
Do what you like. Goodbye.