http://bf3blog.com/2011/08/origin-required-to-play-battlefield-3/#comments
There has been some confusion over how EA’s new
Origin service will be integrated into Battlefield 3. Battlelog plays a big part, with the ability to browse servers and join a game directly from the browser. But according to DICE’s Daniel Martos, Origin will be
required in order to play Battlefield 3 if the game is bought in retail. We don’t know whether this is true if the game is downloaded through a digital download service other than Origin, but we suspect Origin will be required no matter what.
This isn’t a big surprise, as many games these days require a client to run in the background, most notably games from Valve, where Steam is required. However, it can become an issue if the client is draining CPU power, which was the case with Origin during the Battlefield 3 alpha trial. Of course, it was only an alpha, so many tweaks and fixes are bound to happen. Another issue is memory usage among these clients, both Steam and Origin appear to use somewhere around 50 MB of memory during a game (but that can depend on the game and other system specs).
Last week, EA
confirmed that Battlefield 3 would not be released on Steam due to certain Steam rules where DLC and patches must be provided via Steam.