As someone which a strong interest (and little experience) in artificial intelligence I have a short and to the point request for online game developers: allow bots.
Either have specific servers or, if you're single sharded, places in your game universe where bots are allowed. Outside of those servers and places continue your battle against illegal macroing, gold farming and botting:
There's huge potential if people are able to legally run their AI projects in a gaming universe. Witness the popularity of AI programming competitions like the Google AI Challenge, the Mario AI Competition, Starcraft AI Competitions and many others.
It would so be nice to be able to experiment with AI bots in online games without the fear of one's account being banned (and having to spend money on a new account).
This blog post is partly aimed at Blizzard since they represent such a large part of the PC online games market with Starcraft 2, World of Warcraft and, in a few months, Diablo 3.