The one thing that it is doing is really bringing a lot of what the iOS and Android users have gotten through apps into the core OS. The seamless integration of multiple chat and social networks into 1 area is pretty slick, the Bing integration is exactly what a search system should be, and overall there are 500 said features which should include things as custom ringtones so no worries there. Microsoft is playing catchup, but instead of fighting the others head on with an App war, they really are making the Core OS as powerful and polished as possible with an integration of the apps to make everything flow and seamless based on the task you are working to accomplish. That on top of the amazing apps that will now be made with the Mango SDK should make for a nice boost to the already great selection we have already.
Still Loving my HTC Arrive.