So over on the DL forum, the Delta website is routinely (and justifiably) trashed. It's called delta.dumb.

Apparently the US Website is maintained by the same people

Trying to check in just now, when I added myself to the upgrade list it told me the following:

"We're sorry, but an upgrade to first class was not available.
Congratulations! You've been upgraded to first class! Please proceed to
the next page to select your first class seat. If you proceed to
print your boarding pass, your seat will be assigned at the airport."

(Sorry if the message wording is wrong -- I kind of spazzed out before thinking to use copy/paste.)

FWIW, logging back in to look at my reservation now shows me in First(O).

So, what's the verdict? Have I been upgraded or not?