I'd rather make the most of the existing technology. Although the '05 will be basically the same engine w/3 valve heads there will most likely still be some trial and error with the aftermarket and a bit of a wait before all of the parts are available for the '05.
We have guys like Tim & Ronnie who have a pretty good idea of what the 99+ is capable of - personally, unless I just can't help myself I'll keep building on what I have using the existing/improving technology. When the aftermarket embraces the newer mod motor I'll start looking at it more seriously.