Running a quick torrent search, there is a keygen for this game already. Mine was purchased through steam as well (yes, mine is legit). I did the "right" thing and waited for the game to be released and purchased it.
However, having said that... The fact that there IS already a keygen for this game does not bode well. I suspect that the key algorithm will need to be updated and everyone given new keys before this is all said and done.
It seems that the "leaked" version of the game might not have had executable encryption enabled, nor debug threads disabled, thus allowing anyone with a little knowledge of how assembly works to simply observe the key algorithm at work and generate a working keygen.
While I do feel for those of you whose keys don't work, I'd suggest you contact Steam and report the issue, as ultimately, THEY are the ones liable for the sale, not the publishers. The retailers are the ones that have to deal with bad sales.
Read this. Maybe the mofo that made the keygen is actually overriding some legitimate Steam keys? Damn.
I believe they should make the serial link into the account, like the guy in the quote said. Then you can only play with that email. And in case someone has gotten the key via the keygen and a legit one doesn't work, EA shall ask for the physical proof of the key, then delete the user who got the key assigned, and reassign it to the legit mail.
Souds fair to me.
That, or get the keygen, reverse it, get the code generation algorythm and add an algorythm to the verification server that verifies if the key has been taken from the keygen's algorythm. If so, don't accept it. Just like every single game out there does with their onlines.