Essentially, more mature players will be able to enjoy the game more, whilst leaving younger players w/o a credit card/paypal/etc unable to progress easily in the game. And, due to the rapid inflation of money that is going to occur, GAH users are going to be unable to purchase ANY good gear, if there even is any, simply because it's going to take them 40 hours to farm 10 mil. Then, instead of the game being about farming for good gear for your characters, which you really can't do anyways w/o AH, the game will be about where the most gold drops, who has the most gold, and who's selling the most gold.
I really want to see this game prosper and I have enjoyed it thus far, but as of right now, the game is about to be completely !@#$ed, simply because gold can be sold on the AH. It's going to ruin the game.
TAKE A WARNING BLIZZARD; DON'T ALLOW THE SALE OF GOLD ON THE AH, IT'S GOING TO RUIN THE GAME.
Sale of gold will screw gold AH users, whole game will be based off of a real money AH.
Game is %^-*ed. Meanwhile, Blizzard takes money baths on their HQ lawn.