That's very interesting, and it tells that (at least on the PTR if not on the actual live realms) Blizzard can more easily get information from the new dungeon system about which instances players are running. That could have all kinds of ramifications -- if they see a lot of Scarlet Monastery runs coming through, or see that no one at all is visiting Maraudon, we may see even more updates coming to those kind of places. And they can use that feedback for future dungeons as well. It'll be interesting to see what kinds of patterns for instance running arise on the live realms -- obviously there's a lot of interest in the "random" dungeon function (that rewards you for running random instances), but that's still weighted towards what instances you've already done. We may see more changes coming to current dungeons depending on what kinds of information Blizzard gets after the patch 3.3 release.
Patch 3.3 is the last major patch of Wrath of the Lich King. With the new Icecrown Citadel 5-man dungeons and 10/25-man raid arriving soon, patch 3.3 will deal the final blow to Arthas. WoW.com's Guide to Patch 3.3 will keep you updated with all the latest patch news.