I just installed ubuntu 13.10 on a new x1 Carbon (second generation) and everything works fine so far. I adjusted the touchpad to disable "tap-to-click" and enabled "middle-mouse-button" and just fine tuning the touchpad (it is really bad in the default setup).
Now I have two problems left:
How can I make use of the function key bar? I can use F1-F12 just fine, but with "Fn" you should switch the OLEd to other keys. This does not work. Brightness/Settings/WLAN key does not work either.
How can I enable vertical scrolling with trackpoint and middle mouse button. On my lenovo T530 it worked out of the box.
I managed to find a work around by enabling the proposed updates in "Software Sources", otherwise known as "Software and Updates" in Lubuntu 14.04
Check this out; this issue has been fixed if you can't wait for the 3.15 kernel to release
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1309609
Got it working only on the 3.13.9-27 kernel. Tried 3.14 with adaptive keyboard cycling as it should but not returning after resume from suspend.