The best debunking of the fear-mongering about a hung parliament after the May 6 election comes, of course, from Alex Massie, with a great roundup of proportional representation across the globe. Money quote:
The Tories' arguments - or at least the ones they are choosing to deploy - suggest that calamity is the inevitable consequence of a hung parliament and/or proportional representation. This, unfortunately, is poppycock.
I'd like David Cameron to be the next Prime Minister but I'd prefer it if he became so without insulting everyone's intelligence along the way.
Nate Silver also has a compelling new model (serious nerd alert) that tries to predict parliamentary seats from the share of the vote. The traditional way of doing this assumes a uniform national swing toward or away from one party or another, and then translates that into seats. But if you do not see a uniform swing, but one that could provide a major fillip for the Lib-Dems in some areas, a strong Tory showing in others, then all sorts of things become possible, including a point at which Labour sinks beneath the waves. In almost all Nate's scenarios, Labour does worse and the Lib-Dems do better in parliamentary seats.