This is, obviously, a good idea. I think there is an opportunity here to use this as a spearhead to get several ideas into the mainstream about changing how we do in elections.
The highest-profile idea out there is the abolition of the Electoral College in favor of the popular vote. I don't see instant-runoff voting as something that has a chance of being adopted but it can be thrown out there, as well. I doubt getting rid of the Senate has a chance of happening though, so be realistic. Perhaps people would go for a non-partisan (post-partisan?) amendment for changing how we handle the drawing of Congressional districts. Maybe not proportional representation, but something that isn't an incumbent protection scheme.
One of my own ideas is to allow amendments to be ratified by referendum in 3/4 of states rather than by state legislatures or conventions.
Given how the recent Senate appointments have been covered heavily in the news, this would be a good opportunity for the progressive blogosphere to serve as a widely-dispersed open think tank and come up with ideas. What other changes to the constitution do you want to make?