The 3D couldn't be a 1D in a 5D body style, since one of the features of the 1D is the built in grip. (One of it's BEST features also).
So instead of a 3D, for all you FF lovers out there who want a SMALL camera, or a camera to which you can ADD a grip, just tell Canon to put the 1D series AF into their next 5D series camera. No need for a totally new series.
Also whatever it's called, if it's NOT an actual 1D/1Ds body, it SHOULDN'T have ALL the features and benefits of the 1D/1Ds series, esp if it's not going to cost as much. The "best of the best" should have some features all it's own...which is why it IS the top of the line model.