1) Original stories. No rehash.
2) I may be in the minority here but I'd like to see more of the federation. More ships. More of the different designs. More of the inner workings of the federation (assuming it's well done and not another the-federation-is-corrupt storyline).
3) And most importantly: I'd like to have the technical and canon advisers have some real authority. When a writer/director/producer suggests transwarp beaming or says that 78 decks seems more dramatic, the adviser gets to smack 'em upside the head and make them go sit in the corner.
Also, 4) throw a bunch of money at Rick Sternbach and get him to do a big batch of ship designs. Man, do I miss his stuff.
Canon and tech details simply aren't important to drama.
They are when you get them wrong. One of the most long-standing and legitimate criticisms of ST is lazy writing. When they can't even be bothered to adhere to their own continuity, it diminishes the credibility of the script to anyone who's paying attention. If you're watching a show that's set in Florida, in a single story dwelling, and the lead character goes up two flights of stairs and goes outside into a snowstorm because the writer decided that would be more dramatic and symbolic of the character's struggles, would you dismiss any criticism and say that it's only a TV show and those little details 'aren't important to drama'?