I just thought I'd followup with what I ended up doing to replace the FarrAltTab plugin I was using, since I had to disable it to get FARR to load after the .NET 4.0 upgrade...
I hacked a version of an AutoHotKey script to my own tastes. Basically, the real changes are to allow the Window list that pops up be in Z-order (last used, almost...) instead of alphabetical order. This lets you type Alt-Tab-Enter to do the exact same thing as Alt-Tab (switch to the last activated window). It's one more keystroke (Enter), but that's not too big a deal.
So, by using this AHK script, you can pick any window by typing enough chars to uniquely identify it, select it by number (if there's 10 or less windows that match what you've typed so far), etc.
I've attached it, in case anybody is looking for this sort of thing - trying to give back a little, you know...