UPDATE: It seems that Insomniac has taken down the original angry user comment, as long as their comment with it.
If you've been among those that bought Ratchet & Clank: Full Frontal Assault not only for the tower defense styled gameplay, but also for the prospect of one day being able to play it on the go, given the Cross Buy feature, Insomniac has finally commented. The Vita port has at first been planned for an early 2013 release, most likely January.
A month ago, Insomniac had written about their progress regarding the Vita version on the PlayStation Blog stating that they're "hard at work" to finish it. Their Facebook page has been exploding with fan outrage. One such rant, which stated that they lost a fan due to the unfinished Vita port was responded to by Insomniac, stating this:
Please get your facts straight. We never said the 29th. It was said mistakenly via a Sony Twitter account. Not Insomniac. Tin Giant IS a real developer and is working on the game. The game will come out and is not "canned". Insomniac does not develop for Vita. We never have and we have repeatedly stated we won't. Sony owns the game and the IP and therefore controls who makes the games and what is done with it. We made the PS3 version and passed it off to Tin Giant to port to Vita. Anything beyond that we do not control. If you have an issue with that, take it up with Sony. Thanks.
There you have it. The game isn't cancelled, however it is completely out of their hands. Since Tin Giant is the developer of the Vita version, we have to wait until official news is either released by Sony or the developer themselves. However, don't get your hopes up yet, at least the game isn't "officially" canceled.