A Walmart listing for Call of Duty: Black Ops Declassified for the PS Vita may provide some insight on what we can expect from the game (which hasn't been described beyond its branding). Promising the "most intense handheld Call of Duty experience to date," the game will have both the Special Ops Story mode and multiplayer gameplay, according to the listing.
In other words, it sounds like what you'd anticipate from a Vita Call of Duty game. There's no studio listed, but it's likely coming from a contracted third-party studio (in the past, n-Space has done most of the mobile Call of Duty titles). We'll look for more information on this soon.
Walmart has a date of December 31 for release, but that's certainly a placeholder. Black Ops 2, on the other hand, is due on November 13.