At almost every rally for Hillary behind the candidate there is usually a sea of union members holding signs and wearing their colored t-shirts. AFSCME's green shirted members, campaigned hard for HRC in battleground states, and were joined by members of the AFT and the Machinists at most rallies.
I failed to see any large scale union presence at Hillary's speech last night. That leads me to guess they are in the process of negotiating Hillary's exit from the stage. Under no circumstances are they willing to help give George Bush's disasterous economic policies a third term. They'll probably break the news to Hillary soon that they are endorsing Barack. I'm sure they would rather endorse after Hillary concedes, but if she waits too long, I'm sure they'll start the process of switching their endorsements.
A quick check of those three websites show no mention of HRC, let alone urging members to help her fight on, while SEIU and the Teamsters both feature Obama on their front pages. My guess is that in a couple of days, AFSCME (1.4 million members) AFT ( over a million members) and the machinists ( over 700,000) will tell Hillary that it's over and she needs to leave the race or they will dump her.