I don't understand the example, what's the difference between typing "Show me a line graph" and clicking a button in excel that does the same thing.
I found it immediately useful. They've solved some UX and discovery issues around creating charts. And it's not _just_ charts... they're answering questions and identifying trends within the data. e.g. I threw some pretty basic data at this and it told me “Flights” contains a yearly cycle: “Flights” increases until May 1, decreases until October 1, and increases until December 1.
That's pretty handy. YMMV, but this is awesome.