What is MTP/PTP API??
It let you interact directly with connected cameras and other devices, using the PTP (Picture Transfer Protocol) subset of the MTP (Media Transfer Protocol) specification.
Your application can receive notifications when devices are attached and removed, manage files and storage on those devices, and transfer files and metadata from the devices.
A whole new media exchange possibilty lies ahead...
what you gonna do with it..??
More specification about the same can be found on the Android Developer website : http://developer.android.com/sdk/android-3.1.html