Yes and no. Looks like Warhawk is getting an ESRB rating for the Playstation Portable, but it's probably not the Warhawk you're thinking of.
As much as I'd love to see the PS3's Warhawk make its way to the PSP in some form (like using the PSP as a rear view or to play remotely), my sources at Sony tell me there are no current plans for such a beast. Instead this is more than likely just the rumblings of the original Warhawk becoming a PSOne downloadable game on the Playstation Network.
Warhawk ready to fly on the PSP too? [Siliconera]