The 0.5 version of the Nokia N97 SDK has been released to developers. The SDK can be found at http://www.forum.nokia.com/N97_SDK.
This SDK supports all the new/key functionality to be offered by the Nokia N97 as listed below. The most important news about this SDK, and its Developer Library, is that it provides an early preview how to publish content directly to the device homescreen. Both native applications and widgets can take full advantage of Home screen publishing.
New C++ APIs
Homescreen Publishing API
Example app at: HsPWidget (<SDK_Installation_Dir>/S60CPPExamples/HsPWidget)
“Out-Of-Memory” Client API
Example app at: OomExample(<SDK_Installation_Dir>/S60CPPExamples/OomExample)
Sensor Data Compensator API
New Java API’s - JRT 1.4
Sensor API - JSR 256 (New)
Nokia UI API 1.3 (Updated)
New Emulator Features
N97 Look and Feel
Miniview support in emulator Homescreen
Qwerty and Rocker Key support
These new C++ API's are not part of the S60 5.0 platform which was previously released in October, 2008. They will be included in subsequent platform releases. As such, API compatibility with future releases of Symbian is not 100% guaranteed.