New column in bittorrent/peers - bytes that can be downloaded

It would be nice to have column in peers tab: how many bytes could be downloaded from that peer.
Also, on bittorrent/general tab, how many bytes could be downloaded from all (connected) peers.

Maybe also something like "do I know about peers that can serve me all bytes of download", i.e. "download could be completed".

Of course, such counters/status would change over time, as peers are connecting/disconnecting, and status of each peer is changing.