I've been waiting for a while now and heard that it should be within January and even within the next couple weeks...
Someday, but no one knows when.
I'm actually interested in this as well. Even if they only tell us once they release it (which is understandable if they do). Been checking for an update and haven't seen one yet, even though I've heard other carriers have it already.
Only ones that seem to be getting the lollipop update are in Europe and Asia. The U.S. carriers probably have it and are testing it, and in Verizon's case, testing it and adding their bloat to see if it is compatible. It will probably be summer before we see it here on our Verizon phones.