Work on LWJGL 2.x is now mainly going to be stability fixes and just having it working well (so unlikely to get many new radical features). The 2.9 is mostly just bug fixes, new extensions, updates to OpenAL-Soft and moving the project over to GitHub.
For new features, LWJGL 3.0 is where all the action is now, its a radical rethink/refocus of the API, will have many new features, be more lightweight, faster and fully documented. Its still very early days though and far from ready but work is underway.
Snippet from the LWJGL forums
below showing some progress from the current LWJGL3 WIP:
The screenshot below shows one of the demos in the LWJGL 3.0 repo. It highlights one of the most important features in 3.0: multiple, resizable windows. Each window has its own OpenGL context. Both fractals are being rendered with OpenCL, the first on the GPU and the second on the CPU.