m0n0wall Forum - Running m0n0wall on a virtual server, how do I secure the host system?

I am running m0n0wall within VMWareServer on top of Ubuntu 10.04. My box has two physical NICs, both of which are bridged to the WAN and LAN ports of the m0n0wall VM. The WAN port on the box receives an IP address from my Linksys router, and the WAN port on the m0n0wall receives a different IP address.

Eventually, I want to replace the linksys and hook my VM host directly to the cable modem, but when that happens, what is the system going to do about an IP address? Is there anyway to configure the host OS so the physical WAN is ignored and all traffic flows to the virtual WAN?