Hijin25.948: I appreciate those who responded. The problem disappeared the same way it presented itself, with no idea what caused it.
I imagine another characteristic failure of a beta application.
Or merely some hiccup in the internets?
I was yesterday playing Team Fortress 2 on Steam, and twice in the row the game/Steam lost connection to TF2 content servers and I couldn't connect to the official public servers (community servers still seemed to work though). My internet connection was still working fine with a web browser.
Then sometime later, it just started working again. Sometimes these things just happen.