Reference Issue: #2436 (comment)

Basically right now we need to do this:

viewModel = new Observable({
  filter: {
    labels: new Observable({
      apply: "",
      cancel: "",
    })
  }
});

In order for child properties to notify of changes, it's not intuitive and a tad overly complex.

KendoUI on the otherhand manages to have a single root observable and every child property at any level just becomes observable with no extra work... reducing code complexity, potential slack\SO questions... and it just looks nicer

viewModel = new Observable({
    filter: {
            labels: {
                apply: "",
                cancel: "",
            }
    }
});

Kendo Sample: http://dojo.telerik.com/OCUkA