I spent a frustrating few minutes googling (and MSNSearching) for the online class reference and samples for the Whidbey version of WinForms.  I couldn't get any promising hits from my searches.  But a little manual searching turned up the complete reference, as part of the WinFX SDK on MSDN.  There, alongside docs for Avalon, are docs for WinForms 2.0 classes like DataGridView (which is what I was looking for in the first place.)  There are even what look to be some nice samples (haven't tried compiling yet.)

So here's my attempt to teach the search engines that if you want Whidbey / Winforms 2.0 MSDN class reference docs, you go to http://winfx.msdn.microsoft.com/?//winfx.msdn.microsoft.com/winfx/ref/system.windows.forms.aspx