Well let me say that this isn't the first time I've heard the Feb 5th date, and supposedly *somewhere* in a labyrinth of posts is the answer. I can't put myself through the nightmare of searching for it though, so for primary sources I think people will just have to wait for the folk who might know to post something on it.
But the train of thought goes like this: that the Playstation Meeting was never canceled, it was only added on to via this supposed 'surprise,' and the Western gaming press misreported it as being canceled. So if there's anyting out there indicating that the Playstation Meeting was supposed to be February 5th, that would by default be the answer to this question. Be that in an interview, an article, some speech at some show, I have no idea...
Hopefully the answer will present itself. I was surprised also when Metal said Feb 5th with confidence. But Metal and some others though (Z comes to mind) have been following the February event details like white on rice, and I'll defer to them on this and am willing to trust them on a certain level of faith alone.
BUT, like I said *if* there are details behind where the 5th is coming from, they'll obviously make themselves known to us within 24 hours I imagine, because the Internet is a 'fast' place to do business.