When Twitter jumped on the hashbang bandwagon, it prompted me to consider it too. I even did up a quick prototype on Geospike to see it working. Something made me uneasy though, so I put in on ice.
I’m happy I did, as these are some very convincing arguments against hashbangs, and for pushState. Using pushState alone means you can’t support IE, but as the author states “are page refreshes that bad?” – it is possible to make page loads fast, and this is a good example of something degrading gracefully.