First up, Google Maps now allows Hotspot users to add their own rating categories to reviews - eating in a Mexican place where the food and service are great, but the Margaritas suck? Well now's your chance to let people know about what really matters.
The other changes relate to Google Latitude, Google Map's geolocation service. If you have enabled Latitude in Maps, and then enabled Location History for Latitude, you'll be able to view your Latitude history on your Dashboard, directly from your mobile device. This is pretty cool, as you'll be able to view (but not necessarily share):
"...your past locations and visualize them on Google Maps and Earth. See a dashboard showing interesting information, such as trips, frequently visited locations, distance traveled and more."
In addition to this, you'll now be able to check in "at home", and not just when you are out and about. Perfect for letting mom know that you've gotten home safely, or letting friends know that you're in if they decide to pop over for a visit.
Check out Google Maps for Android here.