I'm not a fan of it. A couple of questions:

* How does it rate in terms of accessibility (e.g. for non mouse users, visually impaired, etc.)?
* If there's a footer area, how do you get to it? (see Snat's and Ipstenu's comment above)
Facebook caused this frustration for me, where the "help" link was in the footer but posts kept appearing, due to infinite scrolling, and I couldn't reach the link.