Phoronix: What Not To Expect From The Linux 2.6.40 Kernel
Since the release of the Linux 2.6.39 kernel on Thursday, Linus Torvalds opened the merge window for the Linux 2.6.40 kernel and it will stay open until month's end. While the 2.6.40 kernel will bring several open-source graphics driver improvements (performance improvements, Intel Ivy Bridge support NVIDIA Optimus, etc), new hardware enablement, and other enhancements, there's a few features that you will not find in this next major Linux kernel release...
This allows the LED on some clickpads (and maybe normal touchpads) to turn on when disabled. Furthermore with a xf86-input-synaptics patch, you can double tap the LED to toggle the the touchpad on and off.
This is extremely useful for laptops when you plug in a portable mouse and don't want your typing affected by the touchpad. (Yes I know about syndaemon).