Apple has seeded the latest beta of iOS6.1, bringing the beta count to 3. Beta 2 has been available now for two weeks. If you identify with the registered developers for iOS, by which I mean you are a registered developer, you can now download the latest iOS 6.1 beta from the developers portal.
Developers who have the previous beta installed, iOS 6.1 beta 2, will be able to receive this update as an OTA update. The major additions seem to be APIs to allow developers to integrate Apple Maps into their own apps. This serves Apple in two ways. For one, it will get more exposure to Apple Maps, hopefully getting more people to like it.
Second, more people will, theoretically, be using Apple Maps, which should result in more accurate maps. This is the way that Google has made their maps so great over the years. As more people use the maps, more people are available to submit corrections and updates to make the service more accurate.