In most cases, Lists contains unchanged default lists and export/import is not needed. Modules, which use lists (like FAQ and Feedback for categories) may include export/import with its content. Unfortunately, IPortable interface doesn't allow specifying, whether an export should be complete or filtered (e.g. with or w/o shared lists) and wether an import should replace existing content or be merged with it - i.e. there is an urgent need for iPortable2.

I have never been a fan of supporting core lists - the concept has a number of shortcomings, like missing UI for portal specific lists, no additional attributed (which would be needed for countries, regions, currencies, but also SiteLog Reports etc. Besides, there is still missing an option for localization.