Brent Allsop is currently in this camp.
In this configuration everything will be centered on the single Linux box Xion. There will be 3 NIC cards, 1 for each wan connection and a 3rd gigabit one for the local network. Software will be used for such required tasks as DNS forwarding to the internal network. Nat routing of inbound traffic to the internal network and rerouting of outbound traffic through the appropriate WAN link. The HTTP demon will listen for traffic on all NICs and use a script to reconfigure properly when the WAN IP addresses change.
This would be simpler than using Hal for the second WAN since windows NAT and routing services would not be required to be set up. Xion would be a single point of failure bringing the entire system, including the rest of the home network down if it failed. However, this isn't too bad since Xion is really the only critical part. And once a second Xion mirror box is set up it would be very easy to move this second WAN over to it ' again providing the desired complete redundancy.
Remaining questions and unknowns that must be resolved: