EA Games titles have been automatically added to the Origin service if already purchased on Valve's Steam platform.
Until now if you wanted to play your Steam bought EA Games developed titles, you had only one option. Now though, EA has added these titles to Origin, meaning if you're playing some Battlefield 3 you can jump out and get playing other games like Dead Space 2 without changing platform.
This was first noted on the Day One Patch forums, with user Forsayken saying: "I just booted up Origin today to play BF3 and I see Dead Space 2 there. Why? I bought this game on Steam 4 months ago. I just beat it last week and haven't booted it up since. The purchase date in Origin states Feb 18, 2012 (today). The CD keys match."
So it looks like Origin now knows what you bought on Steam and can twin it with your account. The question at this point is how? According to Joystiq Origin simply scans the file names on your computer and is able to detect whether other games are installed or not. Privacy concerns aside, this sounds like it could be exploited somehow if the information isn't correlated with external servers.
Just give it a while. Someone will come up with a way to trick Origin into giving away free game access.