I've sort of answered your question here. The crux of it involves using auto_mount maps and variable substitution.

Variable	Meaning
ARCH	output of uname -m
CPU	output of uname -p
HOST	output of uname -n
OSNAME	output of uname -s
OSREL	output of uname -r
OSVERS	output of uname -v

Milage my vary between platforms but most modern automout daemons support variable substitution.

An alternative approach would be to use a system configuration tool such as puppet or chef to manage your automout configuration files, especially if you have a variety of versions of Perl (eg 5.8 vs. 5.10) that you need to maintain in your environment since that's not an automout variable.

UPDATE: Added a page about this on my Perl blog. (offsite link) Managing Perl