Mini Would probably be 2.1 and 2.4 and the iMac being 2.1 (low-end 20") 2.5(high-end 20/24") 2.8 (Very high end 24")
I know they're going to, but it's ridiculous that Apple still has combo drives in the low-end models.
I don't think we'll see a 2.4 Ghz mini, for the same reason: product line differentiation.