I've noticed the same. It's only when loading either NPC or player models. However, there seems to be a caching mechanism. After running around Ul'dah for about 10 minutes, the stuttering almost completely stops. Zone out and back into Ul'dah, and it starts all over again.

It only showed up in the last week or so on my computer. Not sure what changed, though I did fiddle with the video settings for an hour to no avail. GPU/CPU/Ram loads are normal (<50%). Also, seems the multi-threading doesn't bridge cores very well. Intel Core 2 Duo, NVIDIA GTX 250S, 4 GB Ram, 2 1 TB 5400 RPM in RAID0 (Win7 Software RAID).

Nice to know it isn't just me though. Knew that hard drive was coming back to bite me at some point. Lol.