Considering the 1D3 doesnt really have much of an advantage over the 7D, I'm sure a 1D4 is around the corner very shortly. Besides build and maybe a better AF system (all depends on how good this 19af 7D is, honestly, most 1D owners are not using all 45 points anyway), I don't think the 1D3 has much to hold on it. I'm hoping the 1D4 is stellar.
7D at 18mp, I hope the 1D4 is atleast 18 as well.