Although i do agree with you with Cube but i doubt the imac is going to stay the same. But i think its going to be hard to top the imac. I think the best guess is that they will give people color options and they will make the imac a lot thinnner. Maybe taking out the power supply and using a more advanced hard drive the 2.5 hard drives that still deliver the 7200 rpm. But what ever the case may be we should almost know for certain that its going to be one unit. I think that at least is going to be a constant.
No WAY!!
They are not going to put in 2.5" drives,
a. because they cost more
b. because this is Apple's Desktop AIO - designed to be what a consumer, not prosumer or power user needs, and quite attractive to switchers. That said they are not going to sacrifice all that storage space for a slightly thinner form factor. 250, 500, and 750 GB drive options vs. what 100-200GB, no way, ESPECIALLY with TIME MACHINE in Leopard, people need space just for that.
Colors yes, Santa Rosa sure, CPU bumps to whatever Intel has in the C2D pipeline, I think they can or will go to 2.4 or so, not much more, I doubt anything else will change before Penryn 45nm based iMacs next year. If Apple can put off this revision till May or June you won't see any major change until Jan 08. Still then it might be the same just upgrading to Penryn and waiting till Summer 08 to go multi-touch.
Power supply, maybe but I doubt it. The chin gives them somewhere to put the logo, isn't that obtrusive on the 20 or 24, just the 17 really and that thing is such a bargain basement model. I don't see them doing that. It makes them much less mountable and all that.