As long as the customer is in the United States, all Packet8 subscribers now have E-911 according to their morning announcement today.
It seems both they and AOL because of Level3's support and partners have this pretty much nailed down. AT&T also has been rather forthright and aggressive in this area.
Vonage though finally went to Level3 for the E-911 service and may also be dancing with Intrado.
I wonder how Skype is going to solve their forthcoming E-911 woes?