Heh, I never heard of TypeScript until this morning when I was reading Slashdot....
I played with it for a while on their website and I dig the syntax. It's still Javascript but much easier to work with. I'm looking forward to installing the VS2012 plugin and start developing with it.
IMO- this, or something very familiar, will become the new standard for web based development. TypeScript + WCF = (my) Future. Plus it's open-source. It may not be as useful to non-JavaScript intensive apps/sites but with all the Phones, Tablets, Dynamic Sites, HTML5- TypeScript is the answer for efficiently writing scaled JavaScript. Will be interesting to see how it develops.