I don't think Steve's ego has fully recovered from his "3 GHz by next summer" statement two years ago regarding the G5. Steve doesnt like being crossed and IBM has really burned him on their promises for the G5.
Another issue is likely that notebooks are out selling desktops which will be a continuing trend. If notebooks are where the money is going to be and Apple is no where near getting a G5 in a PowerBook how competitive are they going to be in the near future?
I can see reasons for the switch but I don't see how Apple can pull it off at this time. Tiger just came out, which means we probably wont see 10.5 for another 2 years. If the rumors are correct, then x86 Macs will come at the beginning of 2006. Are we going to have 2 versions of Tiger? Are people going to continue to buy Macs when they know the architecture is going to change? Are developers going to want to invest the time in money in porting their software once again in such a short period of time?
I dunno. Seems crazy to me but if anyone can do it, Steve can. He's the master of spin. It might be time to buy stock in Kool-Aid (NYSE: KFT) because it will definitely be in demand if the rumors are true.