Ill explain the current focus of the development.
Lordaeron is top priority as its scripts will be ported to MoP and Cata (zones and instances which haven't been changed after cata, which includes most of TBC and Wotlk content + some classic stuff). The other two wotlk realms will be swapped to the Lordaeron core probably before the release of ToGC there.
As for MoP development focus, Heart of Fear has had two more bosses scripted which will shortly undergo testing and Throne of Thunder Heroic is being scripted. As for the rest of the open world, all of the pandaria zones are being worked on, which you may have noticed in the last few changelogs. This will now speed up drastically because the QA team has been data mining from retail (Video footage and other things). As for cata, we are looking into the issue with pets misbehaving after we enabled pathfinding.
Classes are being worked on all the time for all expansions.
Now, getting more into the specifics of Lordaeron and how far we got there:
- All raids have been tested, Ulduar and Eye of Eternity are in the final stages of development (they already work, just polishing up at this point and fixing some new issues). The other raids have some issues but its nothing that cant be dealt with before the release
- Most of the zones have been fully tested (TBC and Wotlk fully, Classic have a few areas missing), an estimate is that over 95% of all quests can be done
- Legendary quest chains are fully working (with the exception of those removed in wotlk, such as Scarab Lord and Atiesh)
- Most of the Classic Dungeons have been fully tested, the issues were mostly damage and spell related and have been corrected already. They need to be re-tested tho because of that
Ill still advise you to ask the players who tried out Lordaeron about their opinion.