Just got my copy of the Google Earth Beta.
I can't test it just yet because I purchased the cheaper NVIDIA-only license for Keyhole that will only run on Chunk (my home laptop) (update: added my own screenshots below).
Looking at the feature list, it looks like this will be a big upgrade:
* GPS support
* new primary database with imagery for Australia, South/Central America, Asia, Europe, Africa, the Middle East, as well as hi-res support for all of Indiana, Missouri, New Jersey, and, Massachusetts.
* 3D buildings in select cities (update: added a screenshot of an awfully pencil-like TransAmerica building in the extended entry)
* integrated driving directions (don't care about this per se, but this is integrated with the flyover feature, which hopefully will be more useful than it's previous "flying morass of pixels" incarnation)
* extension to their previous markup language, KML, which is now KMZ (KML zipped). From reading the descriptions, it looks like it will be easier to create photomaps (both in UI as well as with scripting tools).
It's rather hard-to-tell, though, because Keyhole never released a public specification of KML, and I don't see any released for KMZ yet, either. In the past people have reversed-engineered the XML spec, but hopefully they will be nicer this time around. update: Google has posted the KML documentation and tutorial. (thanks Mickey)
The UI looks a lot cheesier, like some misguided homage to OS X (screenshot), but if the features live up the hype, this should be a nice upgrade from Keyhole NV.
Update: woohoo! There's a lot more imagery for Japan now, and they've unfogged my birthplace (military base). Here's a shot of Mt. Fuji close-up (checkout the extended entry if you want to see a screenshot of Fuji looming over Tokyo Bay):
The flyover driving directions are also sweet -- the map even spins as you go through a cloverleaf. It's mostly an eyecandy feature, though, as it takes about as long for it to fly between San Francisco and San Diego as it does to do the actual driving (even on the fastest flyover setting). Also, they went a little too crazy with the driving directions (in the spirit of Google Maps), which means that you'll find amusing popups like: