Unless they're gonna release it on PC at the same time, then no, it ain't. Pretty sure Ubisoft has been console-prioritized with the entire AC series at the least. I recall past AC releases comin' out on 360/PS3 first.
That reminds me... Has there at least been any hints towards Assassin's Creed III bein' a launch title? ... If there's no sign of it, I'd hope that the conversion between consoles won't take more than a few months at most.
Yup, if this list is accurate it is indeed to be included in the launch: