Unless they have changed, rejections from Howard come pretty late (later than most schools). They also don't have too many folks that remain on the wait list without getting in because there is generally loads of shifting as the year gets later and folks start making up their mind where they want to attend.
Keep stating your interest in Howard and keep positive. Things to go slowly this time of year with the holidays and such. There will be loads of action after the New Year and with the Inauguration, there might even be more things happening to delay decisions.
The good thing is that you got the interview. The bad thing is that the admissions cycle is a long one and it would just be good to know that you are going to be in DC at Howard in July.