The standard edition of Dragon Age Origins is free on Origin for all users of EA's client between now and October 14th, the game normally costs €9.99.
Presumably the decision to make the game available for free is in anticipation of Dragon Age Inquisition's launch on November 18th in North America and November 21st in Europe.
Origins was released in 2009 and remains a great RPG and it'll be yours to keep forever once you download it so if you've been meaning to check it out but haven't had a chance until now, there's never been a better time.
You can access the offer through this link.