This is a great way to show the contributions to a whole in a time series. I made a similar, static graph for the business that was well received. The interactive feature in the NYT version is neat, something I might try out in Excel.
I really loved this visualization so much that I ended up downloading the original data of ATUS thinking I can recreate this in Excel. But the data is too huge and I am not planning to spend more than an hour or two on this experiment. May be during a weekend.
For the curious.. here are some links..
the ATUS data source and tables: http://www.bls.gov/tus/datafiles_2008.htm
Junk charts talks about this too... http://junkcharts.typepad.com/junk_charts/2009/08/degrees-of-likeness.html