The biggest question I had was 'how to build code' ?
One downside: it's in pre-alpha / preview state so no guarantees on how long it will be supported or actively developed. But I think you should at least have a look at it to see for yourself if you would use it in your project.
I know I will.
More links on typescript:
http://www.nczonline.net/blog/2012/10/04/thoughts-on-typescript/ http://wiki.ecmascript.org/doku.php?id=harmony:specification_drafts http://channel9.msdn.com/posts/Anders-Hejlsberg-Introducing-TypeScript https://github.com/borisyankov/DefinitelyTyped