While it may have changed a bit, in 2004, the helicopter curriculum for new accession Marine Corps aviators in the tiltrotor (V-22) track included a reduced ground and flight syllabus.
Where helicopter track included 93.0 hours of ground training, tiltrotor included 58.5. Omitted items were the portions of the curriculum dedicated to instrument navigation and VFR navigation. Since those topics are duplicated in the multi-engine fixed-wing curriculum, that's where the tiltrotor track students pick that up.
Flight syllabus was similarly shortened from helicopter only for tiltrotor. 39.0 hours in the simulator for helicopter track vs. 10.4 for tiltrotor track. Again, the instrument navigation syllabus was omitted and picked up in the fixed-wing curriculum.
In the aircraft, 108.9 vs 59.0 dual.
Solo 4.7 vs 1.0.
Areas that were NOT omitted included such helicopter items as basic instruments, low-level navigation, formation, and tactics. This was still pretty much the program in late 2005. When all is said and done, the tiltrotor students end up with about 30% more training in total before they get their wings than straight helicopter or multi-engine fixed students. Subsequent training for the V-22 I imagine probably takes the better part of a year (as do most fleet naval aircraft, more or less), but don't know.
From what I'd heard, Shawn is correct, a powered-lift category would apply to V-22 or 609 (not that there will be a commercial type rating in the V-22 anytime soon). What's in the test standards and so forth... no idea, though I would imagine some amalgam of helicopter and fixed-wing would be a good starting point.