In order for something like this to be implemented there would have to be a result to increasing rank. Just to show off doesn't cut it.
So we can throw getting better gear as you rank up right out the window. Don't see that happening.
The only other thing I can see is having rank limited servers: n00bs only, or pros only, etc...
The problem here is you are going to get idiots that will make new accounts just to get into a n00b only server and kick butt.
A big problem is there just isn't enough of a player-base for something like this to work.