Eurogamer has posted a article about their visit to Blizzard and a chance at Wrath of the Lich King. It's all summed up like this:

If Burning Crusade was a wild explosion of ideas, then Lich King is shaping up to be a smoothly orchestrated crescendo of them. It brings to mind the elegance, coherence and sense of direction of the Blood Elf starting areas - perhaps the jewel in Burning Crusade's crown - only achieved across an entire continent.

"Northrend's been kind of a coming home," lead designer Jeff Kaplan told us. Despite the fact that Blizzard has been working on WOW non-stop for some eight years now, he maintains that his team is currently "in love with it". As surprising as that it is, we don't doubt it for a second. In every aspect of Wrath of the Lich King, it shows.

The article is a lengthy one and worth reading. It's also accompanied by several screenshots. Enjoy!