Mr. Wheaton has no rights to the "Wesley Crusher" IP.
I've done some work in IP and here's the thing. 99 percent of the time a throwaway reference won't get you in any trouble.
1 percent of the time, it gets you into deep, expensive trouble because you've got to pay for a lawyer to represent you if someone say decides to sue, even if they have absolutely no standing.
A good IP attorney can often run hundreds (In some cases say 750/hour) without including things like paying for his help, research, court fees, etc, etc.
In other words, even a completely baseless suit could just about wipe out a years worth of profit, by its lonesome. not a good risk.