During the Credits
There are no extras during the credits of Mass Effect 2.
After the Credits (spoilers)
After the credits of Mass Effect 2 there is a notice saying that the player can either continue playing the same game and complete any missions that may have been skipped during the first play-though or start a new game with the current character’s stats. There are no extra scenes after the credits, but there is more dialog between characters if you choose to continue and talk to them on the Normandy.
Alternate Endings (spoilers)
There are also multiple endings depending on the decisions the player makes throughout the game. Doing different character’s loyalty missions and buying upgrades can alter the storyline and increase chances of characters surviving the suicide mission. Multiple characters can die during the suicide mission based on choices made and even the main character, Shepard can die. Little is known about how Mass Effect 3 will play out if Shepard does die in ME2 and a save game is imported to ME3; however, BioWare has stated that if Shepard dies, it will transfer to the Mass Effect 3 storyline. Hit the jump to see both endings.