It seems like EA’s digital games storefront will run a bit differently than what we’re used to with Steam. For instance, although it will still be the only place to buy Star Wars The Old Republic that doesn’t involve some type of box, you won’t need to run the thing in the background to enjoy your Ewok-murdering.
“While Origin will be the exclusive digital retailer for Star Wars: The Old Republic, that does not mean that Origin is required for you to access or play The Old Republic,” according to BioWare community manager Stephen Reid. “Origin is a digital storefront, and the desktop application is there to give you quick access to Origin exclusives and deals. However, you won’t need to launch the Origin application to run The Old Republic, nor will you patch the game via Origin.” We don’t know, we kind of liked the convenience of a unified auto-updating system like Steam, not to mention the Friends list and messaging overlay.
Source SWTOR Forums