Well as of right now a lot of character work is probably more or less obsolete. Not to say that it was a waste of time to try to get physics and moves close to what they were in Melee; there have been a lot of pros giving this a try and their opinion would have been very different if things weren't at least as close as we could get them through human processes.I hate to sound annoying but how many melee characters are finished (or can be finished with perfect melee physics) at this point?
But we now have basically all the data on Melee characters that you could ever want thanks to the work of Magus who got them for us, and guys like Dantarion who translated the data into something understandable.
It seems that KB values and stuff translate directly into Brawl (I believe Shell said he's pretty sure they do) but even if they don't directly it is just a matter of finding the conversion for the two games. From that point it is literally just taking all the Melee data and moving it over to PM.
So right now there are characters that are very playable (Falco, Sheik, Mario, etc.) but not quite perfect because it would just be very hard to get everything just right. Now though... Things are going to be sexy.