I doubt it, i think that 360 will get it first, mainly becuase Bill Gates has bribe money to spare.....
I think that developers have gotten used to the PS3, as we see Mass Effect 2, PS2 HD Remakes, Oddworld: Stranger's Wrath, No More Heroes, and much more coming to the PS3.
If Bill Gates couldn't keep Mass Effect 2 under ropes, what makes you think he can keep DLC under-wraps?
Also stated, F3 came out first on 360, if I'm not mistaken, but NV will launch simultaneously, so why not DLC?