I was actually considering the numbered jersey idea a while back, but I don't know if there's enough time to mess with that right now -- we want to get this done before dpcon. Another idea I had would be to have a clan logo that could be used on the front of the jersey, but I have concerns about that being abused, much like the sprays in half-life/CS -- either with offensive images or bright colors that make it difficult to tell what team the player is on. The other problem is if we start using commercial jersey designs, like dye and jt -- I don't think they'd appreciate having their logo covered up by some clan logo. I suppose the custom logos could just be disabled for those jerseys...
Of course, we could go all out and make it like Need for Speed Underground where you can select from a whole bunch of different designs and put them together in various combinations. That would be difficult to regulate, though -- in order to make sure players have enough of their team color and don't do something like make solid black jerseys. It would also be difficult to map the textures so they'd work well and not be stretched/distorted. And with tons of unique jerseys, video memory usage might become a large concern, too...
As for names on the jerseys. That could be done, but as mentioned, spacing will be difficult. Having a different name for the jersey and player would also be complicated as I'm sure people will use completely different names just to confuse people or pretend to be somebody else.
For now, though: one model, one skin, no super fancy features. We'll move on from there.