It might break a number of things, depending on your setup and on what use you make of specific functions. Check the change log to see what has changed and how some functions are handled differently.
If you're on FreeBSD, the following article might help you:
http://perlmonks.org/index.pl?node_id=192255 Basically, just install Perl 5.8.* into it's own folder so you can easily rollback a version if needed. You can then change the symlink /usr/bin/perl to the latest vesion when you're satisfied everything is working.
Personally, I wouldn't install 5.8.0 onto a production server. I would wait until at least 5.8.1 is out.
The only advice really is to set up a test system, install 5.8.0 then test test test. If everything works for you, then great.
But my question is: why upgrade? If you're running problem-free on Perl 5.005_03, why upgrade? Do you need the new features available to you in 5.8.0 or 5.6? Running a later version of Perl is not neccessarily faster, and could well be slower in some areas. The entire package does seem to get larger with every release.
- wil
