Migrating from i386 to amd64

[Shane <shane-debian@cm.nu>]

Hello all,

I've installed the etch amd64 distribution before but now I
have an install i386 machine which is getting its board/cpu
changed out for an em64t unit.  I'd like to migrate to
amd64 on this machine if possible but is reinstalling the
distribution my only option?  It's a devel box so has all
sorts of configured packages I don't wanna redo.  Is there
a migration path available which say installs the 64 bit
libraries and reinstalls the 32 bit packages?

Cheers,
Shane

-- 
http://www.cm.nu/~shane/