Plasma Active on Nexus 7

Touch rotation

I modified the mtev driver to support rotation (my modified mtev-version).
The code uses the function InitTypedAtom from the Synaptics driver
To modifiy the properties, you'll need xinput <= 1.5.4. (e.g. from freedesktop.org)
Seems like that this isn't the right way to do it: as xrandr doesn't support rotation animations or something, rotations must be done in the application and you don't need this driver.

Gyro & Accelerometer

The sensors is in /sys/devices/platform/tegra-i2c.2/i2c-2/2-0068/iio:device0/

Enable with: echo 10 > buffer/length; echo 1 > buffer/enable; (not sure if 10 is a good value there!)
The data can be read from in_accel_*_raw

Contextkit can be used to listen for orientation updates, but I have no idea how ^^