There is much discussion of Obama's first name. B-R-K is an ancient Semitic root, the basic meaning of which is 'knee' or 'kneel'. The sense of a 'blessing' presumably arose because the recipient should give thanks on bended knees. In Arabic baraka is the special quality of a saint which enables him or her to work wonders. Barack will certainly need lots of it, with a virtually bankrupt treasury.
Hussein was Muhammad's grandson, the younger of two sons born to his daughter Fatima and his cousin Ali. The name is specially popular with Shia Muslims, for whom Hussein was the Third Imam (second for some Ismailis). He was killed at Kerbala in Iraq in 680 C.E., when he was trying to raise a rebellion against the Sunni Caliph. This was the martyrdom commemorated by Shiites on Ashura, the 10th day of the Muslim year - January 7th next time.