I'm kinda surprised S&S hasn't been going for more generic covers. That Enterprise, or character shots (though less so Spock than the others) tie the books rather firmly to the original show. Doesn't that defeat the purpose of releasing them around the time of the movie?
How do you define a "generic" cover in that sense? If you don't show the ship or the leads' faces, it's so generic it doesn't even say Star Trek
(unless it's just the insignia or something).
Besides, TOS is still the most familiar incarnation of the franchise -- which is why it's the one that got remade into the current movie series. And people are going to recognize the basic design of the Enterprise
no matter how its nacelles are shaped.