Several things are still not quite clear about this marvelous piece of technology.
a) performance is going to be pretty severely restricted by the ability to make use of the flexibility. We have enough trouble with Category A now for the different types of landing areas (elevated helipad, ground level helipad, short runway and long runway). Now we add the added dimension of an adjustable angle nacelle. I think we'll see only one or two nacelle angles available so there is a limit to the size of the performance charts, if for no other reason.
b) size constraints for operations. Again, alluding to Category A, there are going to be some pretty tight constraints on the size of the areas the 609 can operate from. A lot of oil rigs will probably be out of the question, and other helipads will be under scrutiny. I hope that Agusta/Bell have been doing their homework on this ahead of time.
c) the interface with Air Traffic Control is going to take on a whole new dimension - you can take off from a heliport that probably isn't featured in the normal IFR system and have to feed into the upper airways structure. There are a lot of delays between filing and getting airborne for this type of operation when operating from an airport - how is the 609 going to handle this from an off-airport site? (The V-22 can suffer the same sort of problem - they may have sorted this already.)
d) approach is going to be similarly constrained as takeoff is for performance. The inherent flexibility that the tilting nacelle offers also means that a consistent approach profile is going to be dictated by the manufacturer, and I would suggest that only one or two profiles will be given performance information or even allowed.
We have a long way to do until we unlock the complete potential of the tilt rotor - and I hope we can overcome those obstacles quickly.