Sony's filed a trademark for a title named Gnomageddon, which can't possibly end up being bad. Right? Gematsu spotted the registration which was filed by SCEA on 15th July. The listing stresses that the product pertains to "computer game software", so expect this to eventually appear as a PlayStation 4 or Vita game.
While there's very little other information to go on for the moment, we're going to go out on a limb and assume that this won't be a blockbuster release. The name's got free-to-play written all over it as far as we're concerned, so it could be something similar to Guns Up, which the Japanese giant is also publishing.
Either way, we're sure that we'll learn more soon. Consider our expectations at an all-time low.