Well if I was making the next Star Trek movie or TV show (not to be confused with the relaunch) there are plenty of angles I'd love to see tackled.
What has happened to the Borg? With the end of Voyager showing the destruction of their Unicomplex did the Borg all die or did the Collective simply breakdown? Are their different Borg factions running around trying to assimilate each other??
Aftermath of the Dominion War. Did Bajor join the Federation? What of exploration of the Delta Quadrant? What was the Cardassian Occupation and reconstruction like?
Internal Federation Politics. Unfortunately Enterprise got cut short but I'd love to find out more about the membership of the Federation and the inner workings of the Federation Council.
Allies and Adversaries. What have the Klingons, the Romulans, the Tholians, the Ferengi, and some other would be competitors of the Federation been up to.
Plus the show would have to be a new take on the Star Trek universe with new wondrous adventures and exploration.