• Filter options to dim out/hide unusable items, already-known recipes, and equipment of sub-optimal armor types (e.g. leather for plate wearers)
• Button to quickly vendor various types of unwanted items (configurable):

• Poor (grey) quality items
• Common (white) quality weapons and armor
• Equipment that your class can never wear due to lack of proficiency (e.g. plate items or 2-handed axes for cloth wearers) or class restrictions (only affects BoP items)
• Equipment that is not the optimal armor type for your class (e.g. leather for plate wearers) - (only affects BoP items)
• Bind-on-Pickup recipes that the character already knows

I would also love something like this.