On the Angular 2 documentation page for using the Http service, there is an example.

getHeroes (): Observable<Stuff[]> {

  return this.http.get(this.url)

                  .map(this.extractData)

                  .catch(this.handleError);

}

I cloned the angular2-webpack-starter project and added the above code myself.

I imported Observable using

import {Observable} from 'rxjs/Observable';

I'm assuming the properties Observable are imported as well (.map works). Looked at the changelog for rxjs.beta-6 and nothing is mentioned about catch.