He does have good recommendations for what he'd tell Blizzard to change, though: first things first, he wants to see an official "WTB" mechanism for the Auction House, where you can offer a price not only for what you want to sell, but for what you want to buy as well. He'd also fix the LFG system (and who wouldn't, really? has it ever worked?), and he says that Karazhan was a great example of a mistake -- by putting such a rough, guild-killing instance first in line for progression, Blizzard really put the hurt on players (especially solo players -- he says Karazhan is impossible to PuG) heading into the endgame.
Finally, he's excited for "Lich Kingdom" as he calls it, but not really happy about it: "The only reason that I played up to level 70 was credentials," he says, "and when Lich Kingdom comes out, I shall have to requalify myself." We can't say he doesn't have a point -- as popular as WoW is, competition always makes a marketplace better, and up to this point, WoW hasn't had any competition at all, leaving its faults glaring to an expert developer like Bartle.