I can't find code definition window, some of the refactoring stuff, and some of the debugger stuff. And they appear to be missing from customize-commands too.
I did notice something strange when i was messing around the settings importer/exporter. One of the times I was playing with, there was a bunch of 'key' errors related to this functionality stated above.

Various functionality missing from Visual C# 2005 beta2?
Sérgio Vasquez
Scottah
Patrick Strateman
MaryJaneF
--Oren
Kawish
Newkid
Code Definition View was definitely in express Beta1, and I'm not sure why the debugger functionality would be missing (enable/disable breakpoints) from the menu.