I'm really sorry to be the one to break it to you. You might not possess the fungible assets required for such a commitment -- heck, you might not even like MMOs. These facts don't matter. Cryptic hasn't just made a game based on Roddenberry's magnum opus -- it has managed to create a flawlessly adapted interactive extension of the show.
The demo I recently tried on the show floor of PAX gave me a brief introduction to the various facets of gameplay present in Star Trek Online, all of which directly draw their inspiration from the canon (both spoken and unspoken) of the television series.
The first aspect of the game I got to try out was the space combat system -- having some experience in EVE Online and Earth and Beyond, it's a concept that's not exactly new to me. However, while these titles have adapted the fine art of Earthbound hack-and-slashing onto an interstellar stage, STO has added a layer of strategy which will be unfamiliar to fans of the aforementioned games -- but completely familiar to Trekkies.
Remember in any series of Star Trek when the Captain would turn to the "shield engineer guy" and say something to the effect of "divert power to forward shields?" In Star Trek Online, you can actually divert power to forward shields. Or left, right and rear shields, for that matter. You'll need to manage your ship's energy bank to boost the barrier on whichever side of your ship is receiving the most flack.
There's other aspects of the game which have been snatched up from the show as well. "Thrusters" can be set to "full." "Photon Torpedoes" can be launched into the gleaming belly of a nearby "Bird of Prey." "Lasers" can come in any number of delicious flavors, including (but not limited to) "Tachyon."
My ship was also fitted with three command seats in the bridge -- meaning I had three Ensigns to help me with my aeronautical endeavors. Their help came in the form of three special abilities which appeared in a hotbar at the bottom of the screen. These abilities have lengthy cooldowns, but usually packed quite a punch. One Ensign allowed me to instantly drain an enemy's shields, while another allowed me to fire off a quick volley of torpedos. When used in conjunction, the results were devastating.
My character in the demo was a Tactical specialist, though my fellow crew members fell under the Science and Engineering classifications. As we moved through the space station, I was on the offensive, mixing laser barrages and melee attacks together fluidly. My other teammates fired off the occasional potshot, but mostly assisted me with healing and status buffs. Of course, our roles could easily be reversed, had I designed my team to be heavily offensive and myself to be a bookish tricorder-wielding nerd.
You can just as easliy swap out these AI-controlled teammates out for other player-controlled captains in your team -- in fact, you'll probably need to in order to conquer the higher-end encounters.
I brawled through another combat encounter, and the episode -- that's what the self-contained missions in STO are called -- was finished. I got a brief chance to check out some of the different models of starships present in the game, though I'm not entrenched enough in the Star Trek mythos to recall them all. I am fairly confident I saw every model of Enterprise ever, so try not to worry your pretty little head about the possible non-inclusion of a particular kind of vessel.
Just like in every other MMORPG, what you're going to get out of Star Trek Online depends entirely on what you put into it. If you're a Star Trek buff, you'll appreciate how Cryptic has lovingly tended to the franchise. If you're a sci-fi enthusiast, you'll be thrilled by the species creation engine, which supports the creation of your new genus' historical information. You can even share this information with other players, allowing them to create characters of the ilk you've devised. You could even start a guild specifically designed for members of your homegrown species, if that's the kind of thing that excites you to the core.
Even if you don't fall under these umbrellas, there's plenty of "game" in Star Trek Online for those who've never seen an episode of the show in their lives. However, STO is made for the fans -- and if the game is adequately marketed to the nebulous Trekkie populace, it's going to hit the unsuspecting MMO market like a massive, pulsating supernova.
You could say it set me to "stunned." (Listen, there's no way I was going to write this post without making that "joke," alright? It happened. Let's move on.)