Now you can sign up to receive updates of sattelite image updates.
Simply type an address as you would otherwise in any of the Google map applications, the map will try to find it. The click "select point" and finally you can submit to add it to your list of watched locations.
The procedure is a bit silly, Google could have assumed that most people would want to follow image updates of their own roof and added the "my location" button as it's also available on Google Maps. The "select point" button seems a little bit, .. useless as well. You have already found a location so why not just use that what the image displays. Somethine else nice would have been if the "Dashboard" could show you when the images at the marked locations were last updated.
Now it's just a matter of waiting for an API on top of this, so that the tourism industry can start building a service on top of it and alert a whole mailinglist about updates to touristical attractions in a certain region.
But none of this counts towards the usefulness in a fun kind of way of this little new Google application. It does add a little but towards the Google Map'ing experience. And the name could just be the coolest one Google has ever come up with ;)