Originally Posted by
Betelgeuzah
That's because they're not exactly "sitting on" anything except features that are more or less unfinished which would not make sense to be released in their current state.
Features that take different amount of work to be considered ready, even.
When it comes down to it, they are sitting on the raid dungeon art assets because the monsters are not balanced, as well as sitting on the overhauled STR stat calculations because the VIT stat calculations are not finished.
Further, they are sitting on the roaming NM's and monsters because the servers can't handle the extra load caused by them, and the list goes on.