Just a quick thought on the FCC ruling that PSTN-connected VoIP services must provide the same 911 capabilities as the service they are replacing.
The FCC is right, if services such as Vonage are being marketed as POTS-replacements, then customers should expect that VoIP services will work the same way as the phone they had. Service providers have an obligation to deliver that same level of service, otherwise they shouldn't be marketing their products as POTS replacements.
If Vonage and others had marketed their service as a "2nd phone line for cheap long distance" then this ruling probably wouldn't have happened.
Andy Abramson, as usual, has a nice wrap-up of comments. See: VoIP Watch: Om's Right, Martin's Right, Skype Is Possibly Wrong
Aswath Rao has a different take.