Currently if you want to run Firefox as a native 64-bit app in Windows, you’ll need to use the Nightly channel.* This may change, however. Below is a Twitter exchange between myself and a Mozilla Release Engineer stemming from this post on his blog:
@armenzg I read your Win64 builds blog post. Does what you wrote mean we’ll be seeing Win64 Aurora builds soon?
@jdrch sorry jdrch I suck at twitter. We won’t have win64 for aurora yet. I will ask explicitly to product drivers to enable it there too.
Armen went to school in Spain and is apparently not a native English speaker, so I think what he really meant to say was:
We don’t have win64 for aurora yet. I will ask our product drivers explicitly to enable it in that channel also.
*Note the lack of a 64-bit build for Mac OS X. That’s quite fine with me, I suppose someone else can bug Armen about that 😉