After playing around with GE this morning I'd have to say it's really, really cool (to use the vernacular). I especially like the way the map can be manipulated and the perspective (from overhead to "3D") changed.
Once the satellite and ground images are connected (on Google or MSN or elsewhere) and you can get from the sky to the ground — from space to the storefront — it's going to be mind boggling. Of course, the question still has to be asked: what is novelty and what is utility? I think the answer to that is a moving target as the products improve.
In the context of John Hanke's statements to me yesterday that this was something of a "laboratory" for Google, I'm less confused by the launch of Earth as a client-side app. GE points the way to what we'll see on the Web in the next year or so (at least some of this).
I think that Google is still very much a technology company driven by technology development and this is an example of that. Monetization (although you can buy GE Plus and Pro) will be worked out later — probably in the application of this technology to advertising in the online product. And Google (as well as others offering dynamic mapping) will be very cautious in that regard I'm sure.
I still think the mapping battleground is online, where maps meets the mass audience. But maybe they'll have an unexpectedly high rate of downloads for the free GE. We'll see.