I found out what Suse 9.1 is -- a version of Linux. At X1000forums.com they have an entire area on Linux and someone there has even released an X1000/ZT3000 version of Linux there.
How, HP has introduced for the first time a version of Linux that is preloaded on a HP notebook.
People at X1000forums.com are always discussing among themselves how to get various hardware working properly(particularly the Winbond SD card drive and wi-fi, etc).
So, yes, 64bit is definitely valuable with Linux now but I did not make the connection with Suse 9.1 (as Linux) until I saw this brand (version) of Linux posted today at X1000forums.
But for most mainstream XP users (and XPprofessional) the main 64bit uses right now as the XP2 hardware virus and worm cpu detection options for the Athlon chips only (as Intel has no consumer 64bit cpu out yet).