When to buy an iMac?

So here I am now almost decided on buying a 24″ iMac….  but as usually the “cool” edge has slipped from the current iMac offerings when comparing to the latest offerings in the PC world. I guess I just have to wait till the iMac range is update.  Last thing I want is a 2 month old machine when the next revision comes out… well lets say I hope its only another couple of months till there are revisions.