This gives me an idea for a new Trek show which would be affordable - and possibly quite terrible (or actually decent):
Someone is screwing with the timeline, causing the Federation to cease to exist, so the show follows Federation agents as they travel to different times in Earth's history to fix the problems and stop the baddies. This would be cheaper to produce than a show set in the future, as they could just use the backlot or present day locations, as well as pre-existing wardrobe. One amusing facet would be to see how the world outside their future base has changed each time the agents come back from an operation (assuming their base is somehow "immune" to temporal skullduggery).
I realise this is basically a revival of the unpopular Temporal Cold War (from an insider perspective), but it would be doable, and with good writing it could be good. Quantum Leap has shown this genre can win an audience, and more recently there is the Canadian show Continuum. It could even be a "stealth" Trek show, designed to stand alone but with subtle continuity references for the fans.