In November 2012, Mozilla Engineering Manager Benjamin Smedberg made the decision to stop the development of a 64-bit version of Firefox for Windows. This move upset many people inside and outside Mozilla's community and a month later it was announced that development of the 64-bit version had resumed.
It's been over a year since then, and on the surface it would appear that little has changed. The 64-bit port is still only available as a "Nightly" build on Mozilla's FTP site, and there's been no indication that development will be moving forward to the company's more advanced beta channels anytime soon.
We contacted Mozilla for comment and received a response from a spokesperson: