I neither think it'll be called somethin like 2d, 3d or 4d - my guess it would be some kind of "consumer-ff-body" having a somewhat lower price and dozens of picture-stylez n kind of stuff. the fullframe pendant to 60d.
that would give the product line a whole new sense:
pro-line: 1d (crop), 1ds (ff)
semi-pro-line: 7d (crop), 5d (ff)
(better)amateur-line: 60d (crop), XYd (ff)
it's pretty much the same product-line we had before 7d, just with one more step in between:
pro-line: 1d, 1ds
semi-pro-line: 50d, 5d
probably marketing thought it might be a good idea support the customers who can't call themselfs professional (in sense of profession) enough to afford the semi-pro-line and give them an own segment.
considering the lens, I somehow doubt it will be something too similar to the nikon-lens. I rather guess canon will go to extremes as they did on 15-85 (for crop) and pull out somethin that still goes a step further. taken into account that the 15mm on crop is 24mm on ff, 135mm for ff would be a possible thing - on the other side of extremes it would be a stunning, regarding overall-performance, 24-105 f4 II.
otherwise i'd really appreciate it, if it wasn't a zoom but a shiny new 50mm f1:1,4 L if usm