Trent Reznor has done it: a double album of new instrumental music available as a high quality, DRM-free download, very reasonably priced 2 CD set (US$10) or either one of a pair of luxurious deluxe packages. I’ll be grabbing the 2 CD set myself (yes I’m cheap).
In the mean time you can check out Ghost I, which is available for free (TPB torrent link, as the NIN server seem to be having problems dealing with the digg hordes).