TBH I think we should just buy whats out - I went to the apple store today and several people had already been in an asked about the IMAC's - the same response 'we dont know, could be before xmas, could be after' - I put her in my shoes and she said if It was me, Id just buy one.
The fact is, there hasent been one 'solid utter' of up coming IMACS are we are pretty much now nearly into October.
I kinda agree with the people in the apple store - if something was upcoming we would here more than just rumors here and there by now but something more concrete.
It wouldn't surprise me if something concrete (such as a new iMac appearing in a reseller's price list) doesn't appear until just a day or two before a release, if at all, especially if it's not a redesign.