Well being able to tilt helps with lens diffraction from stopping down to far for DOF wouldn't it?
As to focusing, that's true for sure unless you are using a modern Canon or Nikon DSLR
... since you can use Live View at 10X and scroll edge to edge. LV had changed all that for DSLRs. I'd bet it'd be easier to focus a D3X on this than an untethered MFD back on a view camera out in the field. (Not that the two are equals in terms of IQ).
Don't know anything about color shifts with the Pro full frame models from Canon or Nikon. But both companies offer T/S lenses so I wonder what happens with those?
Clearly, the advantage would be the use of the killer optics available for view camera work. Whether they would be over-kill is another thing.