What is the new projection for Google Maps called?

Google Maps now uses an azimuthal perspective projection (aka vertical perspective projection). Compare this with the general perspective projection used by Google Earth which allows a vertical (as with Maps) or any tilted viewing angle. See wiki/General_Perspective_projection for a description/discussion.

You can tell that it is not an orthographic projection (as per Autumn Leonard) by doing a little GM or GE experiment: Zoom out so that you can see an "entire" half of the globe. Note any small details you can just about see around the edges. Now zoom in from there and notice how those "edge places" start to disappear behind the horizon. And then zoom out and notice how more of those places come into view (even though they're smaller). That is the same perspective you get as an astronaut moving closer to or further from the Earth. Unless you zoom out to infinity --which is what the orthographic projection represents-- you never see truly an entire hemisphere.