I don't get how you conclude that the browser is holding the web back. I think its the people who resist upgrading a decade old operating system or moving to a different browser.
Whilst I'd love to agree, lots of people in my world (the UK insurance industry) don't get a choice.
When reporting issues I often say "Can you upgrade your browser?" to which I get the reply "No, it's what the IT department put on all of the machines, I use (BrowserX) at home though."
How about CSS3 text-shadow and a dozen other CSS3 rules?
IE9 is still holding back the web, especially since it won't run on XP at all.