The fine folks at Eurogamer noted that, during their interview with the recently ubiquitous Kaplan and Brack, some tantalizing hints were dropped about an update to the WoW graphics engine. It's not coming in Wrath, for better or for worse.
"That's actually something we talk about every expansion," he said. "I'm positive we'll talk about it next expansion."
To a degree the World of Warcraft engine is showing its age. That doesn't really bother me very much... I enjoy the semi-cartoon look of the MMO as it seems evocative of the RTS games, especially WCIII, and stands out against a sea of very flat and sterile attempts to make hyper-realistic graphics in games. For all that I would like a bit more flexibility in my character design, I don't mind that WoW has a low polygon count or whatever. But I am very curious as to what they'd do with an updated graphics engine. I believe it was Jeff Kaplan who said, perhaps in jest, "Our designers assure me we haven't even begun to see how big shoulder armor can get."