I disagree, I believe TypeScript/VisualStudio provides a closer experience than AS/IntelliJ. The inference and refactoring work quite well. And they are in their infancy, generics are coming very soon.
Can you give an example of where AS/IJ fail and TS/VS succeeds? IntelliJ's started supporting TS recently and will likely improve. Their whole brand is multilanguage support and they support more languages than any other IDEA. For example, WebStorm 6 added TypeScript, CoffeeScript, and Dart.