.The addition of a new permission (leaving all current items the way they are), that indicates that at a buyer's discretion, they can change the permissions of something from NC/T to C/NT (not the reverse for obvious reasons).
Things like furniture can still be sold as NC/T with no way to change the permission to something that might hurt the seller's sales, but on items like clothing/jewerly/shoes and related the seller could set the permission so that everyone can have their own personal preference by choice.
Thinking about it, I guess this could introduce some problems when dealing with a prim's inventory, but since with clothing it's primarily a prim skirt or prim shoes that usually don't contain any inventory of their own, the impact of that shouldn't be a problem.
(On an unrelated note, I'd love for renaming to be decoupled from having the modify permission, especially for anims where sellers seem compelled to come up with the craziest naming schemes and then sell the anim no modify so it can't be renamed
).