Star Trek Online has only been out about 6 months. I reviewed it back in March, and while it was kinda fun, it had a lot wrong with it. Evidently, I wasn't the only one who thought so as just six months in, as the folks at Cryptic are already offering a welcome back weekend. From August 4th through August 9th, any previous account owner with a valid retail key will be able to download the most recent client and access the game. All content will be available including the new Season Two: Ancient Enemies update.
I might go back and give it a try to see what they've added, but until I hear you get run of your own ship, and a reason to do it, along with real and vital exploration quests, I'm not sure I'll be sticking around.