Quoting marcuslaw:

Quote:
by displaying their thumbnails first followed by 2D BD then DVD.

First things first: Hurray for Showroom-Layout! 

So I played around a bit, and one way would be to create a custom media type (Tools -> Edit Media Types...), e.g. "3D". now give all your 3D BD this type additionally(1) and sort descending by media type. Small possible problem: profiles with media type "Blu-ray" and "DVD" will be sorted first.

A completely other approach would be "Collection Categories".

cya, Mithi

(1) if you switch the media type "Blu-ray" off you lose e.g. Regions.

Quoting marcuslaw:

Quote:
Regarding the creation of a Collection Category, does that require a custom media type exactly match the new category for it to contain a 3D disc?

No.
With Collection Categories you can move any title into a CC, just like you now move it from "Wish List" to "Owned" e.g.

cya, Mithi