One thing I think non-trekkies would want to go for at first would be characters they already know from the TV series and/or movies.
That really depends on what expectations that person has going into things.
If that reader expects that a Star Trek
novel will focus on canonical characters in relatively familiar types of situations, yeah, sure.
If, on the other hand, that reader has been primed to understand that some Star Trek
novels focus on original characters in original settings and scenarios, that reader may well be more intrigued by the idea of something different than what is familiar types of fare.
To make a comparison:
I'm pretty much a novice when it comes to the Star Wars
Expanded Universe of novels. But I'm far more intrigued by the stories that sound like they go off the beaten path and do something a bit different than a typical Star Wars
movie -- Darth Plagueis
by James Lucino, for instance.
At the end of the day, I think the goal should be to give the prospective reader a representative sample of the best of the different kinds of Treklit out there -- both stuff that covers more traditional paradigms, and stuff that goes in other directions.