fwiw i am a hud employee & came in under a different fellowship program (pmf) a few years ago. for my own hiring, after i interviewed, it took 3 months before i heard anything. i know about the honors program but am not sure if it is administered in the same manner as pmf is. if so, i'd also expect to wait a few months...
also, bc congress hasn't approved a budget for us for fy 09, and y'all's salary would be coming out of those appropriations, that may also contribute to a delay. many offices are not able to hire until that final budget is approved (springish?).
so, all in all, i would not worry if you do not hear on a precise date. like i said though, this program may somehow be set up differently than other programs and so you may not be subject to all the delays.