Long Zone Loading Times
We found zone load times increased dramatically going to Windows 7 64-bit, and were significantly lower on clients with solid state disk than clients with a traditional hard drive. It is possible that the graphics settings affect this (better textures is a longer load time) although we don’t have any graphics cards better/newer than an Nvidia 465.
While in other games long load times were probably packet loss as the game attempted to overwhelm the path to the client, causing TCP window collapse, in this case i think the problem is more likely moving the disk head to pull in a little more of the zone, then moving the disk head to pull in some textures, then moving the disk head to pull in some more of the zone (and possibly getting network traffic about players and mobs in the zone and moving the disk head to pull in textures for them too).
If you can afford it, get a solid state disk. And as they say, back up early and often in case it crashes.