When the demo was released, GameSpot posted up a ~30 minute video interviewing Bioware developer Mike Laidlaw about Dragon Age 2. There's an extensive amount of video footage showing your companion Fenris (who is not in the demo). Video, and screencaps of the revealed specialization abilities after the break.
One interesting thing about this video is that you can see the player fiddling with talents, giving us a quick glance at Fenris' unique specialization tree, a couple of Spirit Healer abilities (player mage specialization), and the Blood Mage tree (player mage specialization). Note that the blockiness of the talent images is due to the low resolution at which the game was played in the video