Howto configure the TrackPoint of the Thinkpad Keyboard
To enable scrolling using your TrackPoint read the excellent thinkwiki tutorial.
But in order to get the the new ThinkPad Keyboard (the one without the laptop – just the keyboard) TrackPoint running, use “Lite-On Technology Corp. ThinkPad USB Keyboard with TrackPoint” instead of “TPPS/2 IBM TrackPoint” as a device identifier.
If this still does not work, query xinput using $ xinput list, and search for something that sounds like your device. Use this string for your configuration instead of the thinkwiki suggestion.