Tonight I was thinking back to the first time I visited Red Hat's office in Raleigh. Havoc Pennington (among others) was interviewing me. On my resume I had something about developing a mixed source strategy for Lineo (or maybe it was helping articulate Novell's in Developer Services - I can't remember, and I've since purged all mention of "mixed source" from anything I've written ;-). 
I distinctly remember Havoc reading through my resume, and then looking up and asking with perfect, deadpan sincerity:
"Why mixed source?
I stammered out an answer, but the pride I had taken in my cleverness ("See, you give away the open source code and make money on the valuable IP!") dissipated. Completely. Forever.
Looking back, it was probably that interview, more than anything else, that shattered my comfortable reliance on mixed source. Up until then, I had declared it to be the right way to go in conferences, articles, blog posts (I find this particular one fascinating and humorous), everywhere. After that, I couldn't say it with a straight face, because I no longer believed it.
And all because Havoc couldn't understand why I felt the need to keep my foot in the proprietary door.
Thanks, Havoc. I'm much happier now.