Robin Washington has an interesting article about black/Jewish seders which are gatherings of African Americans who aren't Jewish and Jews who aren't black commemorating their shared oppression. Washington goes on to say that these types of celebrations are held in lots of cities across the country. This is the part that I find the most intesting and it speaks to my own experiences.
None of this is to say those folks aren't sincere about getting along. But the whole idea assumes the dangerous stereotype that all Jews are white and no blacks are Jews, and we'll all be just fine if little black kids can wear yarmulkes and recite "Ma nish ta nah, ha lila hazeh mikol halay lot?" -- or "why is this night different from all other nights?" Likewise, if they're really into it, white Jews get to sing all 250 verses of "Lift Ev'ry Voice and Sing."