Basically till 2006 there will be no real updates. The Powerbook's G4 is like fully overclocked, the iBook's won't be updated because otherwise they will be too close to the Powerbooks and the Mac Mini will likely not be updated. The iBook may get a 64mb gfx and the Powerbook may get a new gfx but i just don't see it, the Mac family is pretty much stagnant for a year unfortunately.
I am all for the transition, it needs to happen (obviously) but it should have been implemented for 2005. Macs in 2007 will be awesome, just rubbish till then.
SImilar situation for the Power Macs, the only room Apple have is perhaps a iMac speed bump to 2.3ghz - that is pretty much the only competitive line unless of course Apple introduce drastic price cuts.