"Controller-As" syntax has different results from older syntax

[DrewML]

Older Syntax:

angular.module('TestApp', [])
.controller('SampleCtrl', function($scope) {
    $scope.username = 'John Doe';
});

Result:

---

"Controller-As" syntax:

angular.module('TestApp', [])
.controller('SampleCtrl', function() {
    this.username = 'John Doe';
});

Result: