When viewing another user's inventory, these new filter options would be immensely useful.

[] Cards I own [] Cards I don't own
[] Cards in my Wishlist [] Cards in my Tradelist

It would be nice for these filters to be available for all other users' inventories when logged in, but I could see restricting it to confirmed Friends' inventories only. Since most or all users use the "Inventory" feature but not necessarily the "Tradelist/Wishlist" features, this could help a lot.

Thanks![/] Cards in my Wishlist [][/] Cards I own []

You can see the intersection of your wishlist/tradelist with their inventory from their profile page. In the trading opportunities section, you can mouse over "Using Tradelist" and change it to "Using Inventory".

Hey thanks, I didn't know about that option!

I think the "Cards I own/Cards I don't Own" filter would still be valuable.