I would get a 1D Mark I any day over a 10D... While that is just me, many pro photographers like it because it shoots REALLY fast, it's very sturdy (weatherproofing), and most of all... FULL FRAME. 1.6x crop on the Prosumer SLRs is really a pain if you like street shooting and indoors like me...
Now if you do more, say, wildlife, and need something that's more tote-able and don't need the full frame, save your money. Yes, it's only like 4MP... But really, unless you're doing poster prints or something, it doesn't matter; the pictures still come out great. Just keep your 10D for hi res pictures when needed.