It would be nice if there was a way to dump all cards from the intersection of two users' wish/tradelists into a trade. When there are very many cards in s bulk trade it can be easier to prune a few from the full list instead of adding them one at a time.

I agree. That is a fantastic idea. I would also like a way to show which cards you are most interested in during a trade.

I am really missing this feature, I have to have two windows open to get everything.