Delta is finally trying to fix the bug I reported over a month ago when doing an award search would show no upgrade status for most people (seemed to affect mostly DM's as PM's weren't having the problem as often).
Now all flights are showing Not Upgrade Eligible. So I suspect they are slowly rolling out changes to the website that should fix this issue. First bring back a blanket status of "no upgrade" and then fix it with the real availability of Upgrade Available or Upgrade Eligible as appropriate.
For reference, this is the thread I started back in May:
http://www.flyertalk.com/forum/delta...-searches.html
-RM