Dragon Age 2 Trailer - Destiny Extended (http://www.youtube.com/watch?v=jlACgYHtWCI#ws)
Really awesome game! I have completed it once. Completed it on Normal difficulty and class was Mage.
Dragon Age : Origins was more of a RPG game. Dragon Age II is sequel to Dragon Age : Origins of course. DA II is more of an action game. Running around , throwing fireballs at enemies and blowing them up.
I really recommend playing the demo and Dragon Age Origins before buying Dragon Age II.
Here are 2 videos of DA:O and DA II gameplay
DA:O - Dragon Age Origins Gameplay PT3 (http://www.youtube.com/watch?v=Lub5e_9NDW8#ws)
DA II - Dragon Age 2 Gameplay HD (http://www.youtube.com/watch?v=v_DHkIo64es#ws)
2 Advices of DA II
There are 2 characters named Carver and Bethany. Bethany is your sister and an apostate mage , Carver is your brother and an warrior. If you want Carver to stay with you when playing , choose Mage. If you want Bethany to stay with you when playing , take Rogue or Warrior. One of them has to die near the start of the game.
If you don't want Carver or Bethany to die when entering the Deep Roads , take Anders with you.
SPOILER
Showing you all the Champion's armours. Just in case you're too lazy to search yourself.
Mage
(http://img696.imageshack.us/img696/6062/screenshot2011032119013.jpg) (http://img696.imageshack.us/i/screenshot2011032119013.jpg/)
Warrior
(http://img846.imageshack.us/img846/4420/screenshot2011032119021.jpg) (http://img846.imageshack.us/i/screenshot2011032119021.jpg/)
Rogue
(http://img852.imageshack.us/img852/2749/screenshot2011032119030.jpg) (http://img852.imageshack.us/i/screenshot2011032119030.jpg/)
There are helmets , hoods and mage hoods also. But they look sucky so I decided not to show them ;P.