What about communicating it to the mainline kernel maintainer?

The -rc3 still does not have the patch for SD cards (mmc).  Has this been submitted to the maintainers?

A project I intend to get working is to use a one-wire network attached to the USB port, using a DS9490 as an interface.  Details of this project, including the code (written in ruby) is available at http://github.com/kim-toms/thermostat/tree/master

GPIO for the one-wire interface is available from http://hobby-boards.com/  The one-wire network is comparatively slow, so it depends on the throughput you need.  I'm going to use it to control a furnace and monitor a few thermometers.

I currently have the code working on a PC under ubuntu, the sheevaplug will let me turn that off, and use less electricity.