Sorry, I feel sort of stupid posting this, but going to anyway.
I use Google Maps from time to time on my Droid, so I know what that is all about, no explanations needed. You can click on satellite view on Google Maps, I understand that. But, I guess since I really didn't use Google Earth on my computer much, I don't understand what Google Earth (when available on the Moto Droid with 2.1 integration, or whenever it's added shortly afterwards) is going to be different from Google Maps.
Thanks in advance.
Oh no! There's already a thread for this!
...but it basically adds a 3D layer to Google Maps. I'd suggest giving it a download and try on your PC. It really is pretty sweet.