Steampowered: 503 Service Unavailable

As of 9:29 AM December 25th, 2014,  store.steampowered.com appears to be “offline” according to “isitdownrightnow.com”, as is the ‘steamcommunity.com’ site.

Steampowered is offering a free copy of Left 4 Dead 2 (promotion ends December 26 10am Pacific), which along with the usual Christmas registrations and Steam engine downloads and installs, is jamming the “store” servers and overloading the ‘Valve’ network. Many visitors are receiving “503 Service Unavailable” errors when visiting the site via browser or the Steam client.  I was able to successfully download and install the steam engine. Everything else, such as validating purchases via email, and gaming, appears to be very slow, intermittently offline or unavailable.

I’m not a gamer, but I play Skyrim from time to time. At present, it appears that there’s the following issues currently:

1. May/May not be able to log into the Steam powered store via browser or the steam client.
2. Email confirmations do not appear to be working (mail server issues?)
3. Cannot get the list of installed products
4. The Steampowered store “Blog” is offline/inaccessible.

There may be other issues I can’t detect from here.