KDE SC 4.5 is about to be released and KDE SC 4.6 is being discussed. However, Martin Graesslin has revealed some details about what they are planning for KDE 4.7.
According to Martin's blog post, they are looking at OpenGL 3.0 to provide the compositing effects in KDE SC 4.7. OpenGL 3.0 provides support for frame buffer objects, hardware instancing, vertex array objects, and sRGB framebuffers.
This is what Martin wrote:
In a next step I want to go to OpenGL 3 in 4.7, but the free drivers do not yet support this generation. (That’s perhaps a point to work together with Compiz developers.)
Other than this, Martin also gave some insights about their plan for KDE SC 4.6. With KDE SC 4.6 they are aiming to improve the performance of the compositing effects already introduced in KDE SC 4.5 and clean up the rendering code and port it to OpenGL ES for the mobile edition.
You can read more about it in Martin's Blog.