Play Services are no longer supported in pre-Gingerbread devices, the Mobile Ads SDK has been included in Play 4.0, and Wallet Instant Buy offers merchants a new integrated purchasing system.
A notable change in Play Services 4.0 is the discontinuation of Froyo support which won’t get new Play updates. Google mentions as an argument the fact that less than 3% of all Android devices use Froyo or earlier.
An enhancement appearing in Play Services 4.0 is the inclusion of Google Mobile Ads SDK. After an application is updated to use this SDK, the developer won’t need to push any other update to devices in the future because the SDK will be automatically updated on all devices with the Play Store app, without having to wait on carriers to update the OS. The SDK can be included with apps deployed to devices without the Play Store app, but it won’t be automatically updated in such a case.
Developers can monetize ads through the Mobile Ads network on all major mobile operating systems: Android, iOS and Windows Phone. The SDK will include support for other advertising networks soon - DFP, Ad Exchange or Search Ads for Mobile Apps-, according to Google.
Google Wallet Instant Buy offers merchants the option to process purchases through Google Wallet and Google+ sign-on, a system monitoring transactions for fraud detection around the clock. This service streamlines the entire purchasing process, the users not having to fill in billing and shipping addresses each time for different applications, the information being provided and maintained by Google. Currently, the service is available only to US merchants.
The Maps and Location services have been improved to consume less battery and to be more responsive.
Play Services contains a number of services – ads, authorization, Google+, games, maps, location, wallet, panorama – which are automatically and transparently updated by Google, bypassing the carriers which proved to be slow in pushing updates of the OS to devices. This approach is meant to deal with platform fragmentation, to make developers’ life easier, and we can expect that more services will be included in the future.