Cathegories are good. One thing to note is that some programs may be visual in several cathegories. Like OOo draw may be linked in both Office and Graphics (MSOffice users dont know OOo can draw) And gcompri in both games and education (very few know gcompri at all, but my 4 year old son think it is both)
What i have seen as an obstacle for new users, is to get going with post-install. People are so very grown into the idea that they have to surf the net, download manually, double click the file (... and then often not have a clue how to get rid of it later...) I think a icon "How to manage programs" on the desktop to a html page would be good. (And also one about how to connect to internet) (both should be a local file in case internet is not up, but with a well visible link which the user is suggested to choose; a link to a mageia wiki page as we try to keep the wiki updated, and he can surf the wiki for more) There it first briefly explains the idea of repositories. What each contain. (and Link to how to add extra.) How to start drakrpm and use it. About the automatic and manual updating. And (because drakrpm displays the question) explanations of orphan packages. And a link to advanced sections: about dependencies about meta tasks about dkms I suggest also to talk about migration methods: Import fonts About *Office files Browser links How to use mail program to import from a windows mail program, ( or alternative technique such as upload using ISPs IMAP, whatever) Maybe talk about useable sharing services on the net, like: DropBox, Evernote, Operas Unite and shared links, etc ...And of course we should have a desktop icon taking the user to main Mageia site and there link to wiki and forum :)
