game explorer categories tags

Customizable categories, essentialy the option to create sub-folders, would be cool, if not necessary, to have in the Game Explorer.
I intend on eventually having all my collection of 100+ always-on-disk games and about as many emulated ROMs in there :)
just add a "Tags" field to the Game items so we can reach them from Windows Search as well; "games emulated shoot-em-up" for example, would bring up all the Space Invader and Darius etc clones :)