Medium sorter for the filter display on the left:

[EazyCheeze1978]

Why not put in a Medium field for each platform, allowing us to enter which media the platform takes and then sort the platforms that way? Similar to how Platform Categories are handled now:

Call it Platform Media, and it would look a little something like this:

(top-level) Card (subordinate) NEC TurboGrafx-16 (subordinate) Nintendo DS (top-level) Cartridge (subordinate) Nintendo Entertainment System (subordinate) Nintendo Game Boy (subordinate) Nintendo Game Boy Advance (top-level) Compact Disc (subordinate) Nintendo GameCube (subordinate) Nintendo Wii (subordinate) Sony Playstation (subordinate) Sony Playstation 2 (subordinate) Sony PSP

And so on and so forth. (note that handheld systems and consoles would be listed together with this sorting) And for computers that have more than one type of media available (Floppy Disk and Tape as per Speccy, Commodore 64 etc) they'll just be listed under both media.

Also, it might be awesome then to introduce a Medium field for each game, and the ability to edit the field en masse such as by selecting multiple games at a time like is allowed with many other things currently. This would be used for another left-side sorter called Game Media, which would simply have a list of the defined media types in the Medium field: Card, Cartridge, Compact Disc, Floppy Disk, Tape etc. and selecting one or more of them would filter the collection to show only those media types in the list.

If this is coming as part of the new custom playlists, awesome! But if this has not been considered yet, I think it'd be cool, at least. :)