A CBS owned channel would be the most likely outlet. Why? No one else to share the revenue with. Direct syndication, ala the TNG model would be 2nd most likely outcome. A 3rd party cable channel is least likely, and a premium channel (as previously posted) is not a good fit for Star Trek and will not happen.
A new series is a few years off from now. Development takes years for a high concept, big budget show. Plus, it will still be viewed as a risk given that the last series (right or wrong) was canceled. Risk won't be tolerated until advertising revenue picks back up after the current recession. At the earliest, a TV show will first air between Reboot Movie 2 & 3 (ST12 & 13). Probably after 3, definitely if there's legal issues outlined along the lines of what I describe below..
I just searched on the internet. The budget for Enterpirse was about $1.6 million per episode. The budget for Stargate was $2.2 million however when it comes to Stargate. MGM would pay 2/3 of the budget while keeping the DVD sales proceeds. Maybe the same arrangment can be made. Since after all if more people tuned into ENT in it's worst days then SG-1 on it's best days. Sci-Fi would win with the advertisers,CBS would get the DVD sales and the fans will get a show that isn't under a constant threat of canceling which won't lead to anymore 7of9s.
Maybe I'm just being naive.
You're not naive, but ST has more convoluted licensing than most properties. CBS owns the TV & media rights to ST, so TV series (past and future), books, toys/collectables, and video games. Paramount owns film rights and distribution rights, or past/new movies and DVD sales.
What's interesting, is that CBS may not automatically have the rights to base a new TV series off of Paramount's movie. They might have to pay Paramount to do so. Trek isn't unified under one entity like it was in the Paramount->Viacom days. It's split, and when things split, lawyers get involved and it all gets complicated. We aren't privy to the contracts, and there's a chance things could get dirty. It may be legally easier (and one less royalty to pay) for a show to be "Prime Universe" based. All these things have huge impacts on the subject and viability of a TV show.