Depends upon the kind of unity that you want.
If you want all taekwondo to be unified under one organization with a standardized curriculum and sparring rules set, forget it. Not going to happen. The cat is already out of the bag and there is no putting it back. You can have a unified curriculum within a single organization, but you will never see the ITF, WTF/KKW, ATA, ITA, whatever other organizations are out there, plus independents unite under one banner, one curriculum, and one sparring rule set. Each is already invested in its own system and will not give up that system in order to unite.
Really doesn't matter; the KKW is the largest organization and is hands off enough that a school can be "KKW" and still maintain its individuality. Not really much incentive to split off unless you simply want to make a statement or keep grading fees for yourself.
Now, if you want to have numerous organizations and independents united under banner of taekwondo, that is possible. Kind of the way that there is quite a large number of ryu that are all called karate, there can certainly be a variety of similar Korean arts called taekwondo. At this point, that is pretty much what we have anyway.
Once you get above the level of the school you train at, it makes little difference unless you have Olympic aspirations (portability of rank is nice, but I think that a much bigger deal is made of it than it really is). Students will go where they feel the most comfortable. Those students that are looking for a self defense oriented taekwondo will gravitate to schools that promote self defense. Students looking for the best place to train in order to make it to the olympics will gravitate to the appropriate school. Everyone else will go to the school with the most convenient location, the schedule most suited to their lifestyle, and maybe the best price.
Daniel
