Right now I think there are bigger problems than full-fledged bots playing at the tables. I'd be more concerned about people colluding, using multiple accounts, data mining, or using HUDs that automate certain decisions (beyond what HEM2 or PT4 provide).
Computer scientists have 'solved' heads-up fixed limit hold'em, but games like full ring NLHE are much more complicated, and probably won't be solved for quite a while.
If people have written full-fledged bots for full ring NL, they probably use strategies that are easily exploitable.