The Linux Foundation, Linaro, and others have been interested in merging more of the out-of-tree work by Google on Android back into the mainline kernel. This would ease things for developers, manufacturers, and others. In the past, attempts at merging key Android changes have failed or ended up in staging but to only then be un-maintained. This time around, the mainlining effort has been working out better and more changes are set for the 3.4 kernel.
John Stultz of Linaro published the latest Android update patches for the Linux kernel staging area to be merged during the Linux 3.4 kernel merge window. The mailing list patches begin here. Of the changes in this staging pull isn't anything particularly exciting but Android work on the RAM console and persistent RAM. This work doesn't include the recent Wake locks work that's still considered a proof-of-concept for an upstream implementation.
Outside of the kernel, if you missed it, there is now a Java-based X11 server for Android.