The official developer blog at the World of Warcraft site has been updated by Systems Designer Greg "Ghostcrawler" Street. The team is beginning to list out some of the systems and features that it's looking at for future tweaks. Street issues a caveat by saying that this is a preliminary list and not necessarily all-inclusive.

PvE

We’re happy with damage overall. We have very few traditional tank and spank fights (even Argaloth likes to parry melee) so it’s hard to get consistent numbers without very large data sets. Still, we see Survival hunters and Unholy DKs on top of a lot of single target fights. Arcane, Marksman, and Beastmaster damage is too low. Retribution, Shadow, and Fire and Frost mage damage might be too low, but we’re still watching them. We aren’t seeing a lot of Subtlety rogues in PvE yet, so that sample size is still small. On fights where there is a lot of area damage, Demonology warlocks, Frost DKs and possibly Survival hunters are all too high. Shadow priest AE, mostly due to a weak Mind Sear, feels too low.

Healing in PvE is working out pretty much as intended. There are some Heroic dungeon bosses that are probably tougher than the required item level average permits. In general, you might have a tough time upon zoning into a Heroic dungeon with a bunch of strangers as soon as Dungeon Finder permits, especially if your group isn’t willing to communicate and work together. We want Heroics to be challenging -- if you want to zerg the content, stick to normal dungeons.

Tank balance overall seems good at this point in time. Threat seems to be in a good place -- good tanks don’t have much of a problem, but they can’t “phone it in” either. We’re seeing all four tanks get a lot of use, even on Heroic raid fights. That could change as more guilds are able to make serious heroic attempts.

Read more here.