Sounds like a nice thing to have. The value, for me at least, would be the benefit of a true standalone firewall, bringing with it the possibility of a real, physical, DMZ.
With such an enhancement to my own network I'd worry a little less about allowing visitors to use my internet connection. I'm usually too polite to refuse, but I do worry.
An extra firewall and DMZ would however address many of my concerns about whether their devices may contain malware that's about to trash my servers, or whether they may want to run applications and services that I would never trust myself, such as skype.