EA have announced that there will be a demo version or prologue of Dragon Age II released on February 22. Good news for all potential slayers of dragons and heroes out there, here's a description of the demo courtesy of the press release:
"In the demo, players will venture through the game's prologue, choosing from three different character classes. They'll also learn more about Hawke and hone their skills and abilities that will make them the ultimate hero. After finishing the prologue, players will enter a key new location in the world of Dragon Age, Kirkwall, befriending Isabela, a romantic interest in the game who is also a deadly smuggler. Upon completion of the demo, players will unlock a special weapon, Hayder's Razor, an ancient dwarven blade which increases health, mana, and combat abilities, in the full release of Dragon Age II."
The press release did not mention any specific platforms so we assume the demo will be released on all platforms.