In a fit of carelessness, I decided to pull one of my test notebooks to current unstable, including the Xfree 86 => X.org migration. To my surprise, the migration was not only absolutely painless, but the new X server worked on the first try. This is a new experience with X11 for me.
Splendid work, Guys! Keep it up!
After the weekend (where I need my main notebook to be operational), I am going to try moving my main work vehicle to X.org.
The update of my main work notebook was as painless as expected after the test with the unimportant box. aptitude, clean up dependencies, and you're back in business. On the first starts (from the command line), fonts were broken (too large), but after rebooting and logging in from kdm, the fonts are ok again.
To my astonishment, xfree86-driver-synaptics works fine with X.org as well.