You know what I would love? If I could record games I play with a particular deck. There should be a feature that lets me specify stuff like what colors the deck I played was, and and major cards I remember having issues with from the opponent's deck. If you played against a person who has a deckbox profile you could list that they used one of the decks on their profile and the results. I could get stats on win/loss ratio and could keep track of what kind of decks and cards my deck is weak against and strong against.

A very bare-bones version of this would be fairly easy to implement, I imagine, and even a simple one would add an entirely new dimension of functionality to the site.

This sounds cool, we'll think how we could implement it nicely.