Enabling the Thinkpad middle click scrolling in Ubuntu (or another system using the evdev driver) requires a different process than I referenced before. It's still very easy though, it takes adding the following to

/etc/hal/fdi/policy/mouse-wheel.fdi

<match key="info.product" string="TPPS/2 IBM TrackPoint">
 <merge key="input.x11_options.EmulateWheel" type="string">true</merge>
 <merge key="input.x11_options.EmulateWheelButton" type="string">2</merge>
 <merge key="input.x11_options.XAxisMapping" type="string">6 7</merge>
 <merge key="input.x11_options.YAxisMapping" type="string">4 5</merge>
 <merge key="input.x11_options.ZAxisMapping" type="string">4 5</merge>
 <merge key="input.x11_options.Emulate3Buttons" type="string">true</merge>
</match>