Is it normal to interview for faculty positions in December-February and not hear back yet by the end of March?
Commiserations -- the job search is tough.

If they haven't gotten back to you by the time they said they would, it most likely means you are not their first preference candidate. They probably have already made an offer and are waiting to have that accepted or rejected. You could still get an offer as their second/third/fourth/etc. preference.