Judging from the berserk level of posting at this announcement on DPR there are quite a few who are deciding, not between the 10D/D60, (seems a no-brainer, for new purchasers ;-), but between the 1D/10D.
Given that the gap is only (!) <$2000-or-so, and that the next step-up(1Ds) is another 4 grand or so, that option is out for many.
The other features we can pretty much figure out from the reviews, but a direct image quality/enlargement potential between the 1D/10D could be helpful, if you're willing :-)
Kinda curious about a real-world evaluation of Canon's claims for the new "engine"'s effect on enlarged-image quality.