Over in the land of the official forums, Jason King has posted an introduction to ArenaNet's Live Response Team. The basic idea of this small group of developers is to address and fix a good portion of the bugs found in the game world, as well as fix exploits and monitor player concerns in the forum and game. He overviews the process of how a game bug or exploit goes from "submitted" to "fixed", which includes determining the severity of the problem, reproducing it, handing it off to the appropriate member to determine a fix, then finally dousing it in harsh quality assurance tests. The time-consuming process is emphasized often, as great care goes into making sure no other bugs are introduced as a result of another bug's fixing.
Another interesting note is the mention of monthly achievement improvements. While most of the content addition notes are kept "hush hush", it's mentioned that the goal to increase these types of small changes will become possible once the game is clear of major bugs.
Remember: A bug report a day keeps the dragons away.