Offline access to iCloud Calendar and Contacts?

I don't understand the question, sorry....

If you mean, can I see the events and contacts that are already on my local machine from the times this worked fine, the answer is yes.

When I open iCal (I guess I should say, properly, "Calendar") or Contacts now I see the previously added events and contact, but I get the "Contacts can't idenfity the identity of the Server" alert, and when I click "show certificate," it's at that point that the incorrect/unknown/wrong certificates show up.

I hope I answered your question...

My response above was IN ERROR. I thought I was responding to something else, so please accept my apology.

Everything seems fine to me, but sure sometimes there are a few regional issues. Just wait a few moments and try it again.

See also: http://www.apple.com/support/icloud/systemstatus/