As stated in a comment on my previous post, the FL4 livedocs is available from 1 month now.
While testing Flash Builder 4 (I won't comment here about the good and bad thing of this product), I noticed you can filter the AS3 reference to one or more runtimes.
Flash Lite 4 is one of them !
Good thing if you dev in Flex but want to port it to FL4 (I know, it should be Slider's job).
So, we now have all the docs....We're now waiting for Slider and FL4 based phones (HTC Desire?)