Microsoft is going to release the next version in SharePoint with the name of SharePoint 15 [i.e. in express mode]. Recently they released the interoperability API Documentation of SharePoint 15 Technical Preview version and it contains what's new. I didn’t go through it and will update once I knew everything.
You can download the SDK from SharePoint 15 Technical Preview Download .
Hope will get more flexibility on it. Thanks to Microsoft team [SharePoint team].