I think NDAs are common when reviewing final hardware to ensure that all the different reviews show up at more or less the same time. Otherwise, there's a mad rush to be the first to get one up once the first review boards go out, and there's an unfair advantage to the sites that happen to get their boards first, or that post crappy, hastily written reviews. You'd probably want to give each site several days to play around with the board and write a decent review.
So that means if no one is under NDA yet for the final GFFX samples, it's unlikely we're going to see any reviews this month. Also, given the rush Nvidia is certainly in to ship this product, they're probably going to want to send the review samples as soon as they have stable and well-performing hardware and drivers. Since there's a big difference between sending out a few working samples and shipping in mass quantities to retailers, there will probably be a few weeks gap between the appearance of the first reviews and the availability of the retail product.
Assuming the first reviews appear in early to mid-Feb., the March 9 date listed by BFG for its GFFX pre-order sounds like it will be around the earliest you can expect to get one. The early Feb. date listed by PNY doesn't sound very realistic.