AidenShaw said:...A new mini-tower with a Conroe just makes too much sense
I think you just sealed it...and not in the affirmative.
The reasons you listed are definitely there, I've found myself thinking those things more than once. I don't want to try and read Apple's mind here, but they probably already see the iMac as filling the "void" between the Mini and the PowerMac. Has Apple ever really offered an intermediate system before?
Like you say, it just makes too much sense for it to happen.