Upcoming kernel updates for Apple products -update
According to Ubuntu's Apple forum there will be support in the kernel for Apple's Magic Mouse. It can be seen at the Github website that code is being produced for this intelligent mouse. Karmic Koala users can download a patched kernel here. Another user alexmurray from the same forum came up with code to improve sound on the MacBook (Pro) 5,1 and 5,2. Whilst sound works for MBP5,1 / 5,2 under Karmic, it could definitely be better - mainly the master volume does not affect the headphone output, and the speakers don't automute when headphones are plugged in. This has now been fixed.
Two more models (MacBookPro 5,3 and 5,4) were added to the mbp_nvidia_bl kernel module. This will hopefully help to make an end to the backlight problems on these models. It can be seen from the module that for a lot of Mac models, backlight should now work (MBP 3,1/3,2/4,1/5,1/5,2/5,3/5,4/5,4; MB 5,1/5,2; MBA 1,1/2,1).
Furthermore Benjamin Herrenschmidt released a libata driver for the "macio" IDE controller used on most PowerMacs and PowerBooks. It supports all the features of its predecessor (drivers/ide/ppc/pmac.c), including mediabay hotplug and suspend/resume. It should also support module load/unload.