Microsoft's MIX10 conference kicked off a few hours ago in Las Vegas and already it seems that Windows Phone 7 Series is set to be the star of the show. Company executives took the stage today to show off some of the platform's features, including a built-in location and push notification system, along with a number of prototype and early-stage applications from the likes of Compatible phones won't be ready for a while, of course, but developer can use the PC emulator to start coding. Later this year they'll be able to sell their programs using a new Windows Phone marketplace, which will support one-time credit card purchases, mobile operator billing and advertising-funded applications. It will also allow customers to try applications before buying them and developers will be able to cross-promote their applications through deep linking.