what I really want to see, as it says "Star Trek Online" as opposed to "Starfleet Online" is different paths.
of course there will have to be the ever popular Federation Starfleet path, but I would say also include the basic 2 others, Klingons and Romulans as paths. on top of that I would use a skill based ssytem as opposed to what PE had, which was class based. In otherwords, do something similar, but not as intense, as EVE. where a player chooses a Template through character creation, and would get basic skills from that and then can train up in various other skills. Therefore a Player could start off as an engineer, but at some point decide he wants tactical or command skills as well, he could just train them. Along with the three basic races versions of Starfleet, there should also be the a civilian path for the player as well, this would entail merchants, free exploers an other things we've seen in Star Trek along the years.
This set up would allow for easy controlable expansions to the galaxy, for instance the first expansion could the Orion pirates, Cardasians, and ferengi has playabl races, the next could add the Tholians, Gorn and some other as playable. along with adding playble faction races, they could add new ships, and sub races within each Faction Empire (so feds could start off Human, Vulcan, Andorian, but then add bajorian, tellaxian, ect in the expansions). this also allows for lateral grow, as opposed to the vertical grow other games do. instead of trying to foce more "end game" content in, this would allow for more "main stream" content and more areas for seasoned playersto explore, but their skills might not be right for a new border, so they would have to learn more skills for that. imagine having to learn bajorian energy systems, cardasian sub neutronic relays, ect after you've hit the so-called "end game". so basically expansions add new playable "main stream" content as well as new skills.
anyways, that's what i envision and would like STO to be like.