More than likely a complete error but who knows.
Activision stated not so long a go they had no Vita games in development but I wouldn't say no to this so can always hope. Cant be as bad as the last Maybe we'll learn more during Gamescom as thats when Declassified was shown...
Out of interest, what is Sledgehammer up to now who helped develop MW3?

The Spanish wing of GameStop has listed a version of Call of Duty: Ghosts for Sonyís handheld. So far, nothing has been confirmed about the Vita version, but given that itís coming to all current and next generation home consoles, it could be making its way to the system.
Gamescom is in just two days time, so if weíre going to hear anything about it, weíll find out then. The game is out in November though, so itís quite late into development if true, surely.

Now, if this was Tesco Iíd be taking this as very likely, as they were the ones who initially leaked Ghosts. But itís GameStop, who have a history of listing nonsense, such as recently with Assassinís Creed Rising Phoenix.
Itís an interesting one, anyway, and itíll be good to see that if it does exist, whether itís another poorly made spin-off like Black Ops II: Declassified, or a down-specced version of the full game.
Maybe itís true and, in that case, it shouldnít be declassified just yet.