Casey Hudson, executive producer on Mass Effect 3, has said those playing the game through Origin need not worry about any intrusive DRM, and furthermore, they can absolutely play the game offline.
Speaking with CVG, Hudson said Origin isn't any different than other digital services out there, as it allows access to digital featured PC game "have now."
"We use Origin, and it's interesting because really, it's just a way to get access to the online and digital features that, you know, generally, PC games have now," he said. "I think people are going to be fine with it.
"I think that the people who try Mass Effect 3 on Origin will realise that it's not an intrusive DRM scheme. It's just a way for you to sign up for the online services that you're going to get on an ongoing basis through Mass Effect 3. Just like you get with any other kind of online digital distribution, or multiplayer or whatever. It's not something that requires you to always be online - you can play Mass Effect 3 offline."
The game will require a one time, single authorization, and installs will not be limited.