Nope--sorry. As of right now, the DRM of Sony's LRX files has not been circumvented. Sony has said that they are going to be converting everything to ePub, and at that time it sounds like you'll be able to download your book in ePub format. But that might not happen for a while. (I think I heard December).
Also, the nooks aren't due to ship until 11/30--if you're willing to wait over a month to finish your book, you might be able to re-download the ePub version from Sony, strip the DRM and then load it on your newly arrived nook.
dordale