This is a cool idea brought up by myself and a few other players (credited at the bottom of this post, sorry if others contributed and I missed it.)

Much like the K/D Ratio on the high scores for PKing, I think we ought to have a ranking system for stakers on the high scores as well.  Also, to up the ante (pun absolutely intended,) I'd like to see a betting system put into place.

Outline of Staking System:

• Ranking System:

In addition to the Victories/Losses, named ranks would be a good addition.  These could be anything from "amateur" to "gold glove" or anything we can think of really.  This will also give betters a more confident choice when putting their money on the line.

• Scheduled Stakes:

For those who wish to participate in a ranked stake, they will be prompted to schedule it.  This way, no one misses a chance to place a bet.  5 minutes to half an hour should be sufficient enough for people to make a decision about their bets.  For scheduling, there could be an option in the duel screen to "Schedule" and options such as 5, 10, 15, 20, etc. minutes that the two parties can agree on.  When that is done, a message is sent out globally.  To prevent additional global spam, I also propose an option in the Wrench menu for disabling staking announcements.  I'd guess a time cap of an hour would be a good idea so people aren't waiting around for hours for a stake to commence.

• The Pot & Winnings:

The pot will be set up much like the AH, with an option to place or remove a bet on a specific scheduled stake.  Within a few minutes of the stake (1 or 2,) there will be a "last call" to place or remove bets.  This prevents people from losing their GP if they wish to withdraw from the pot.
The winnings will be split up evenly among all players who placed bets on the winning staker.  In addition, the winning staker will receive a small percentage of the pot (something like 5%.)  This gives even more incentive for players to stake.

• Rundown of System:

-Betting system addition to AH, or a separate NPC in the AH building.
-A scheduling option added to the dueling screen.  Upon scheduling, a global message is sent out, with a player option in the Wrench menu to disable/enable it.
-Small percentage is given to the winning staker.  Remaining pot amount is automatically split between winning betters.

Contributions:
Snosaven24
Canabisativa
Madboxing1
Hotlava
and other players probably because I have a terrible sense of awareness.

EDIT:
Afterthoughts:
Bet minimum.  To prevent people from betting 1GP and then reaping a much larger reward.  The minimum amount should be high enough to ward off those who wish to play the system, but low enough to be an option for as many players as possible.