Upload & Sell: On
There will always be a conflict between sensor density (ppd) and frame rate (fps). I expect that the unifying theme is that future Canon 1D-series bodies will all be full frame. The 1DX is a kick-ass, full-frame, high-fps, moderate-MPx body. The 1DXs will be a kick-ass, full-frame, moderate-fps, high-MPx body.
Like the 40D, the 1DIV occupies a "sweet-spot" in the Canon lineup. In the case of the 40D, it's happy circumstance. In the case of the 1DIV, it's the predecessor to a transformative change from high-fps, 'crop factor' 1D-series bodies, to high-fps full frame 1D-series bodies.
Ideally, I'll sell my 1DIV a few minutes before the 1DXII is announced. More likely, it'll be a bit later.