If you talk about lexical analysis of the text, what do you have in mind to use?
What would be good is to ask users to categorize their content (let's say 20 items). From this point on an analysis tool could analyze the existing content and the new content, look at the categories and add it automatically to the appropriate categories in the category system. Or at least set the default to a certain value.
Concerning the browsing widget, the issue here is that you will have to touch all the queries in the packages to support a "and category_id ...." structure. So having a widget which lets' you limit the items in displayed in each package to only those which match a certain (and/or linked) categorization is not the big issue. It is the support within the packages that is giving the headaches.
If OTOH you mean, you want to browse the content by category and package, this is already in the categorization package. You are limited though to the title of the object and (soon?) to the description, which each package should be able to fill in.
