I am considering hiking the PCT in 08 (or if I can save the money fast enough, 07).
Southbound seems to make more sense to me--I wouldn't have to start until I know that the snow situation is managable, and I wouldn't have to fight the desert during the summer. starting in mid-June, I would have around 3-3.5 months until I was risking heavy snows in the sierras, and would want to be out of them by the end of September. 2000 miles in 3.5 months seems perfectly managable, even comfortable to me, after thru-hiking the AT this last year. I would then have the luxury of taking as much time as i wanted to finish the trail, and even turn back and do some of the sierra again if I had plenty of time.
Also, if I went SOBO I could possibly hit the trail in '07, and I'd much rather be hiking than working.