Vonage already allows users to register their location so that 911 works.
I recently signed up with SunRocket and their registration process requires one to fill out the physical property address tied to the phone number so their e-911 service can function properly.
Private enterprise responds better and in a more cost effective manner to its customers than to our government.
Yep, the major VoIP providers are doing that now. (Vonage, Time Warner, etc.) My cable connection is highly reliable - only down once or twice a year over the past 5 years - but it's still not as reliable as my landline. I can't see ever losing the landline altogether.