I would highly suggest you take on the daunting task of rewriting crappy code on CPAN, rather than trying to fill a niche that isn't yet filled. It is easier to find bad code, than to find a legitimate niche that you know enough about to fill. Rewrite any CORE module with modern practices, some good examples of code that needs rewriting is URI, or HTML::Element. Those modules are essential and the code base is a total mess.