Xenon is high end mac pro but that has slowly been outdated by the new i7 chips. I would assume that the iMac uses the new extreme i7 quad in the high end models considering the new alienware laptops are doing the same. MacBook pros use everything but the extreme chips (battery life purposes) in the past, but the iMacs do the same and allow extreme upgrade because they are plugged into the wall. Xenon is a custom chip that is a nethalem altered "slightly" for the mac pros. A slimmed down version probably wouldn't happen because that is an old chipsets. Think more towards the newly released intel i7's