Yup, that's it. It's just a definition file, same as the ones you can find on Nuget for jQuery, etc. Same as those, in Visual Studio you can just drag it into another typescript source file to create a reference and have intellisense available. Works same as JavaScript files in VS - creates this commend at the top with relative path to the definition file (*.d.ts are all TypeScript definitions)
/// <reference path="../typings/jquery/jquery.d.ts" />
/// <reference path="../typings/kendo.all.d.ts" />
Hopefully, parts are still buggy I've found. Each TypeScript version seems to break something, but fix something else. The Kendo definitions are pretty complete - think there's only been one or two points where I had to change their supplied definition file (forget where, but something declared as a {}, switched to 'any' so TypeScript would allow me to could extend it).