The Soul Sacrifice Demo is now out on the PSN Store in North America. Its completely free to download so try it out! It was also stated on the Playstation Blog that the save file in the demo can transfer over into the full game. This means you can level up you character in the demo and then continue from that level in the actual game.
The demo features some of the bosses and spells available in the full game. You can even play the demo online with up to three other players. Try it while you get the chance because the online for the demo will end once the full game comes out on April 30, 2013.