Should give the current pve tier as transmog in different color ofcourse, first items 1,5k-1,8k, 2k head, 2,2k shoulders etcc
That'd do more bad than good. People would just flame Blizzard for putting PVP second and rehashing old models. They already get enough stick as it is for recolouring and reusing old models.
Tabards take 1/100th the time of recolouring a PvP set and would make 99% of people happy. Have a 1500, 1750, 2000, 2200 and 2400 tabard. Could also (as someone said in another thread) either reset the achievements or award new tabards every season for hitting those ratings to give people the incentive to hit those milestones.