First dual specs, a topic hot on everyone's mind. He provided some new insight into how things will work. In particular he said that "It will be trivial to do in town. You will also be able to do it out of towns, but not as trivially." This is new information and should make everyone tingle with gleeful anticipation at how trivial it might be to switch specs while in Dalaran.
He also makes mention of things we already knew. They are aiming to allow people to swap glyphs and action bars with the dual spec feature, and that it should be along ideally in the next major content patch.
That patch cannot come soon enough.
In addition to the dual spec information, Ghostcrawler went into some points on raid difficulty. While there isn't any really new in terms of how difficult the raiding environment is (or isn't) and what may lie in store for the future (a harder Ulduar raid zone), there is some new news about loot tied to achievements.