I wanted to give Linux 3.7 a try on my GoFlex Net and after some patching, I finally got it to compile.
Based on linux-kirkwood patches (some had to be slightly modified - include correct headers), it compiles for every platform linux-kirkwood 3.6 supports. However, I only tested it on my GoFlex Net and it seems to work fine.
It might not have a perfect .config, so don't blame me if your favorite modules are missing.
And don't blame me if it renders your system unbootable.
It already includes BFQ patches, but no AUFS since they did not update their patches yet. (Could anyone explain what AUFS is good for on a plug computer? I don't get the point)
If you are willing to test Linux 3.7 on your Kirkwood device, know how to compile a kernel (well, yeah basically just run makepkg) and how to restore your old kernel if the new one fails to boot, simply clone my Github repo.
Have fun!