TypeScript versus CoffeeScript

I saw half of a talk by a Mr. Jed Mao at the JavaScript Austin Meetup Group. The meeting was inside Volusion and Transverse sponsored (i.e. bought pizza for everyone). The talk was on Node.js but it delved into TypeScript too. Jed has authored an app in TypeScript and Node. Someone in the audience asked "Why TypeScript and not CoffeeScript?" or something comparable and Jed replied that he preferred TypeScript because it, as a language, was just JavaScript with some extra type semantics which compiled to JavaScript. If you dropped regular JavaScript into TypeScript it would compile and moreover just compile to an exact duplicate of the TypeScript code. The code for CoffeeScript is its own beast which cannot be mixed with JavaScript to be compiled to JavaScript. There is, thus, a heavier learning curve to commit to with CoffeeScript.