Zev Shlasinger of Z-Man Games answered this very question yesterday to a geekmail I sent him:
"As for Endeavor, it won't be until late Spring or early Summer at the least. So far."
From the wording, it sounds like the release could slide even later...I pre-ordered this last month when the estimated release date was December/January and now that site says June...I guess I'll be canceling the pre-order and wait & see what develops. Any one know the reason for the delay?