After I installed Visual Studio 2010 beta 2 (hot off the presses) in a VMWare virtual machine (you don't think I'd be crazy enough to install it on my real machine did you?) I noticed some serious performance problems with the text editor. It was very laggy - couldn't keep up with my typing - and had some visual glitchiness.
I've seen similar problems with WPF apps (including our own, running in VMs before) so I had a sneaking suspicion what a solution might be. I tried my stock fix, and sure enough the editor became right snappy.
The fix (well known by some, I'm sure) is to disable hardware acceleration by creating the following DWORD registry value:
and setting it to 1, as described here. Restart Visual Studio (doesn't even require a reboot) and you should be good to go.