All of the XML processing modules on CPAN are based on expat, including XML::Parser, XML::PYX, XML::Simple, XML::Twig and many more.

I fail to see why it is such a problem. Yes it means you cannot install directly using CPAN. But it installs very easily under Unix and once again XML::Parser comes with Activestate's Windows port. I know CPAN is extremelly convenient but it is not the only valid method to install modules.

If you want to do any serious XML processing you really need a proper parser. Using regexps is false laziness. It is akin to not using strict: good for a quick hack but a no-no for anything serious.

Incidentally there are good reasons why expat is not bundled with XML::Parser anymore. It is used by other applications, Apache for example and bundling it lead to incompatibilities between the different versions and problems building them.