Doubtful, Ulysses is probably African American while the Courier can potentially be as Caucasian as one can get. I doubt there will be any sort of family relationship.
I for one don't think the Courier has even met Ulysses, or even knows who he is is. I find it likely that the Courier unintentionally did something that had a great impact on Ulysses' life without even realizing it. There's only so many ways Obsidian can approach this story, the Courier is a player defined character who doesn't have amnesia, so they're probably not any different in New Vegas than they were back then, and in New Vegas you're not railroaded into being a jerkface.
I... really like the idea of the indirect relationship. It hadn't even occurred to me before. Then again, I've been so caught up with being terrified of Ghost People, that my lack of openness isn't surprising. It'd still potentially affect the PC's history/backstory, but even when role-playing in the best environment, you're thrown for so many loops, inadvertently doing something in the past wouldn't be TOO bad...
All in all, you're my new hero.