i have now an amd64 bit cpu, and i'm using debian. but it is at the moment no easy to get progs and tools....like wine for 64bit.
how is it on arch linux?
Look around the forum, there are lots of topics concerning AMD64 out there. Shortly: there is no AMD64 ArchLinux port (yet?), so everything would just run in good ol' 32 bit mode on 64 bit boxes :-)