The interview asks some pointed questions about the problems encountered with TBC and what Blizz might have learned from them. How about the daunting attunement and access difficulties that hardcore players encountered when they first loaded the expansion onto their computers? Kaplan points to how they realized that access to the instances needed to be tweaked and they did so with recent patches. Blizz would like to have world events that include the whole server again, much like Ahn'Qiraj (and I couldn't agree more, as long as the guild that opens the event doesn't do it on Monday morning like they did on Elune), and they are looking to avoid with Wrath what Kaplan "personally consider[s] a mistake in the Burning Crusade."
In addition to world events and the possibility of unlocking an attunement for all a player's characters once one of them has achieved it, Kaplan also says they are looking into improving the trade skills with Wrath. He points to leatherworking as an example of a trade skill that received little lovin' in TBC. Essentially leatherworking became obsolete as players entered Outland and received dropped items that were superior to anything they could make. "In the Wrath of the Lich King, we want everyone to be satisfied with the trade they choose and we want it to be rewarding. Therefore we're going to analyse[sic] everything we did with The Burning Crusade and previously to work out what was good and what was missed out."