Except that I was at that session, and can definititely report that Marissa Mayer (yes, that's how you spell her name) was not at the session despite being listed as a speaker (last-minute change).

If you're curious about what sort of thing you can't find through the Maps geocoding API by name, try searching for "madison square garden." It's an iconic venue for NY, and yet, just not available. In Google Places, however, it comes right up.