Does the traffic shaper work with more than 2 interfaces

From PFSenseDocs

No, in pfSense 1.2.x, the traffic shaper is limited to two interfaces. If you have an install with more than 2 interfaces, traffic on the additional interfaces will not be shaped and will render the other shaping useless, or at least much less effective in most scenarios. You should not use the shaper with more than 2 interfaces.

In pfSense 2.0, the shaper has been rewritten to accommodate multi-WAN, multi-LAN, a combination of the two, and any other multi-interface deployment.