I have a demo coming up for InfoPath, and I needed some information on the Visual Studio integration with InfoPath.  I stumbled across a great site:

http://www.infopathdev.com/

I cliked on the Resources tab, and saw all the downloads for InfoPath (including the component I was missing, the InfoPath Toolkit for Visual Studio .NET).  Nice.  I didn't immediately see this information on either the InfoPath Developer Center or the InfoPath home page, and multiple searches on the web didn't yield anything.  Nice job.