I seem to actually remember an idea similar to this coming up a while back.
The main problem I see with any system like this is it could serve to fundamentally divide the PS player base. Sure it would all still be on one server but, one essentially carved into factions. Believe it or not, some of yesterday's "power levelers" have grown into some pretty great roleplayers and even some "hardcore RPers" like to go to the arena to hack 'n' slash a few things for a change of pace. With a game mechanic that essentially labels every person's character I am not sure that people would even be given the chance to evolve into a person that RPs. Any purple dot that went anywhere, found some red dots, and at least tried to have an IC conversation would probably be largely ignored, get frustrated, and say "screw these RP idiots!"
Besides, If you think the whole PLers versus RPers debate is bad now... just wait until you split them up into what is tantamount to gangs.
Scene, Kada El's Tavern after The Great Dot Civil WarPurple Dots storm Kada El's!
"Alright guys, let's kill these RP wimps!" "%$&#, They're all declining to duel!?"
Red dots all wave their hands, magically making and throwing god-modded pink fireballs.
"Hah, you guys are all dead!" "Get out of our tavern you foul beasts!" "Go back to the arena!" "((but dude, they're all RP dead)) "((hehe, oops. Arena = DR))."
The Purple Dots:
"What are you idiots talking about?!?!?! We have way better stats then you!" "Stop declining our challenges Noobs! I already got a warning for spamming!"
The Red Dots:
"((We beat you, we all have super amazing powers, earned from Roleplaying. You're all dead! Be gone!))" "((Plz, just type /die already... can't you see you lost?))
The Purple Dots:
"Oh my gawd! You Reds are such losers!" "Let's get out of here, go kill some ulbers or something."
The White (OOC) Dot people while running in circles and spamming /greet /sit and anything else worth spamming:
"hahah, omg that was funny xD" "d00d what a bunch geeks!" "Ah! %&$* brb, my cat just barfed on my keyboard. ><"