I have CONFIRMED that Dragon Age 2 saves use the same setup as Dragon Age Origins & Awakenings. I have SUCCESSFULLY edited my save using the same method described by Minuos (using unknown v2 resigner). So far, I have changed my character's name in Dragon Age 2 (savegame.das, savegame.met). I know its not much to brag about, BUT, the save did not corrupt.
FYI....I used Xplorer USB to extract save from drive, Horizon to get the contents, Hex Workshop to edit, unknown v2 resigner, and Xbox 360 Hash Block Calc to check if proper was "true" (I did not calculate).