Very good MMORPG for casual players, MMO dabblers, and people who normally don't play MMOs.
Right now there's not a lot of extra content besides the missions and leveling up to keep you interested for a long time, but, if you're like me, you may find yourself taking long breaks from the game after your initial play period, just to go back for a month of two to enjoy the game so more, and repeat. The designers are adding in a crafting system for costume pieces and enhancements (used to improve super powers in place of armor) that you can sell over the upcoming auction house.
Speaking of the designers, they're extremely player friendly. They recognize a player's need for new content, and they release large free content updates regularly. The content updates are filled to the brim with new stuff, with additions in the past including new archtypes (classes), new areas, new mid level and high level content, new mission types, and new power sets. The designers also interact regularly with the public, especially on their forums, and they listen to the ideas and problems the players and take them seriously. They're very good at responding to people's problems with fixes. They care very much.
The community is extremely friendly and helpful, mostly because it's a game many casual gamers get hooked to so there's not a large sense of elitism. Considering the game is often based around team work, most people are intelligent, friendly, and helpful. There's really no one whose overly obsessed with the game like with Everquest or World of Warcraft, so the message boards are full of player guides and friendly conversations. I recommend you give it a try, atleast for the first free month.