Retail might be great, but leveling 1-150 (or whatever it is) with 3 or more expansion missed is quite a wall to cross (i quit after TBC, played 24/7 at 60 cap). I've seen offers of starting at level 130 or something, but then it feels like i've skipped years of content and have no clue about where everything is in the world. No experience with all the new stuff added and if its actually good or not tho.
This said, i like the simplicity of classic wow... easy to step into and every zone is filled with players. I wouldnt start playing WoW again if they implemented 'classic feedback' into a new expansion, for me its just simple nostalgia and enjoying the little things like player interaction, playing the auctionhouse and dueling friends in front of cities.