I can't see any difference, so what exactly is the diff betwixt XP Professional and XP Home Edition?
There are three basic differences you might notice, plus lots of other more detailed ones, all business related, see
here.
The three you might notice are:
Networks: Pro will join a domain, Home is restricted to using workgroups.
Security: Pro has file/directory level security where you can encrypt and restrict access to files by individual user.
CPU: Pro supports multiple processors, Home doesn´t. I am not sure if, or how, that is relevant for the new dual core CPUs, as I only use Pro.