When I fired up Visual Studio 2005 this morning, code editor appeared to have hung in midst of typing. After trying different keys, apparently the problem was strangely limited to a few special keys and commands (backspace, delete, return, ctrl-X, etc.). Even more strange, I could delete text using Edit > Cut menu command via either the menubar or context menu.
After freaking out for good 10 minutes restarting VS2005 and uninstalling recent additions like Orcas, I came to my senses and searched to find fellow victims of crappy engineering workmanship. Aha. Apparently the problem was wide spread when VS2005 was in beta so I had to dart past that cloud of noise before finding Peter Bromberg's post, Loss of Keyboard functionality in Visual Studio 2005 — and a FIX!, and John Pollard's Delete and return keys not working in Visual Studio 2005, the source of the fix.
As instructed, I blasted the content of "C:\Documents and Settings{username}\Application Data\Microsoft\VisualStudio\8.0" folder then reset VS2005 settings via:

Tools > Import and Export Settings > Reset all settings…

menu command and now the all keys are firing again. Whew. Apparently, VS2005 settings get screwed up sometimes which in turn confuses VS2005's keyboard event handler. What a piece of crap.
Thanks to both Peter and John for saving my morning from turning ugly.