I favor ideals that are real time past TNG/DS9/Voyager. 12 years since Voyager aired its final episode, 10 years past the movie Nemesis. It would be far enough from the other shows to have its own independent story arc. Going way too far ahead means you have to make the Technology starts getting super advanced to satisfy fan expectations. Have to say your ships can do Warp 200 or Phasers can destroy whole planets and Transporters can beam 200 lightyears away. Can cross the Milkyway within a commercial break. I would like to only keep it slightly more advance than the 24th century shows. I know about the Warp 10 limit, but who is to say some now Warp Scale gets invented (Like "All Good Things" had the Enterprise doing warp 13). Gene Roddenberry kept limits on how fast starships can go so the Galaxy seems to be a big place. Sill have to keep it to where it takes years to reach the Gamma and Delta Quadrants and parts of the galaxy remain unexplored. Then again, you can also make your ships just fast enough to reach nearby Drawf Galaxies in the Local Group.
Being real time Passage past TNG/DS9/Voyager leaves the door open of bring back someone from a prior series without an excuse of time travel or was frozen somehow. Many fans do want to see some connection and is a good way to draw interest to the show. A new series has to draw in new fans from this time to be successful, have to make it relevant to 2012. We know what happened in prior shows, new show has to tell us what is happening now with Humans, Vulcans, Klingons, Romulans, Cardassia, Borg, and invent new races as well. You have keep that consistent threat there.
We are well aware that the JJ Abrams movie refined the timelime, but that is an alternate reality. Who is to say history did not reset before the TNG era.
I thought about an ideal to where a new threat is not coming from another race, but within the Federation itself. Planets declare Independence from, cause a civil war, Earth and Humans no longer the center of it. The Vulcans or Betazoids take it over. Do the enemy comes from within type arc.