well, calling one CMS a 'standard' might imply that it would be supported!
I think we can list quite a few here, and note whether a department might support CMS X. But until & unless a CMS is used centrally or someone offers free support to others - I think we're still in a wild west/every dept for themselves situation.
I also would hesitate to put all our eggs in one basket - so to speak. I like the diversity that is going on out there with regards to CMSes.
We have Liferay, Drupal, Joomla!, Drupal... and a whole slew of other open source applications using the templates out there. Which I think is great... but, there are some others which are not in public repositories for other WDN members to utilize. :-\
The largest obstacle to a centrally supported CMS is centrally supported web-services to run a CMS on -- which is non-existent atm unless you pay a dept for that service --- at which point it <em>is</em> supported in some sense.
Just some of my thoughts regarding the issue.