One of the more interesting features of the new game engine is that it gives the developers the ability to both import old art assets and create brand-new ones for the game. "Since AO is huge, for most assets we don't have time to remake them," Williams explains. "The new player experience, for example, has all new assets. Most things won't."
He also mentions that the team is finalizing some issues regarding the upcoming server merge and that this winter's holiday content will go live in the game next week.
[Thanks to David for the tip!]