If you live in Europe, you can get the x64 ScanSnap software if you
provide the info from this Fujitsu page:
'Fujitsu | ScanSnap S510 | FAQs'
(The IP is registered to Fujitsu Europe, and I verified that with
Unfortunately, Fujitsu Computer Products of America said that those
drivers were "European only" due to "different hardware", that I could
be put on a mailing list and x64 drivers should be out "by the end of
this  year".
If anyone from Europe (or outside) wants to try to get these drivers
and test them, I'd be curious to see if they work with non-European
hardware and how well they work overall.