I find it very funny that people think another ten watts from the CPU will suddenly cause an iMac to melt down. Boys there is a lot more to the power budget than the CPU. Stick modern hardware in an iMac and you might actually lower overall power disapation due to new RAM and a system chip.
As a point load the ten extra watts on what was a 55 watt load isn't impossible to deal with either. Sure a different heat sink is required but does that surprise anybody. Or is anybody surprised that Apple would try new technology here? They could be looking at anything from carbon fiber to heat pipes to a woman with strong lungs. The point us that ten watts on a point load is not a significant problem.
If this is in fact an iMac in a new generation case then it should be obvious to everyone that thermal considerations will be taken into account to address any thermal issues that may exist. With the iMac line now focused on larger and wider screens thermal management should become easier not harder.
As to why Apple needs to deal with more heat in an iMac it is pretty simple, they lack a midrange solution. That is they need a platform that offers better than laptop performance to fill out the middle of the line. That big hole between the iMacs and the Mac Pros performance level that everyone talks about.
I agree. Its doable either by beefing up the cooling or perhaps having other components that generate less heat than current components do.
In any case Intel are now releasing mobiloe quad core chips with prices that fit within the iMacs budget. I'm now convinced that one way or the other the iMac (at least some configurations) will go quad core at the next refresh. I hope that the 20 " machine at least gets the BTO option if it isn't a standard configuration.
And the reality is that Apple is running out of ways to freshen up the iMac lineup without adding quad core chips. I guess the could just add the NVIDIA chipset but that would hardly be an update worth mentioning. They're really at the megahertz ceiling with dual core chips. Moving to quad core chips is the natural progression at this point.
In any event Apple could put an i7 in the iMac easy, it is nothing more than an engineering problem. I'd be happy if they did but also surprised. Surprised because of the priceing structure that would result. Maybe the top end. The problem is in a few months everybody will have i7 on their check off lists for acceptable hardware. Apple needs an i7 play even if it is not the iMac.
IIRC the currently available i7 chips are power hungry 120 watt chips. With some engineering they could adapt them to iMacs but it would likely require some extreme measure to cool like heavy duty fans or a much larger enclosure. I don't think that's necessary with the new low power desk top quad core chips or the mobile quad core chips.
I agree that in 7 months Nehalem CPUs will be a must have item for a new machine. But around that time I expect Intel to release either low power Nehalem desk top CPUs, mobile Nehalem CPUs, or both.
Then it'll be time fro a new refresh.