Turns out that Motorola support page may have been right after all
After a puzzling update to Motorola's support documentation for the Droid Bionic that indicated it would receive Jelly Bean in Q2 2013, soak test registration emails are being sent out to some users for the update. Soak tests, if you're not familiar, are a last level of testing with a small portion of users willing to give new firmware a try before it moves out to everyone. Like previous soak tests, this is a good indication that we're headed towards an official release of the update to the general public soon.
Remember though, Q2 just started a couple of days ago, so if previous updates are any indication we may be waiting a little while to see it all out there officially. The soak test registrations go out to a small number of people and won't be available for long, so keep an eye on your inbox if you're expecting to see one.
More: Droid Bionic Forums; Thanks, shayne6717!