I'm not sure I agree with the general thrust of Ray's Nanny State blog on the Texas Attorney General's E-911 lawsuit filed against Vonage under the Texas Deceptive Trade Practices Act. Having in mind the grandstanding tendency that seems to be endemic in some generic--or maybe genetic--way in some of the state AGs' offices, and not knowing everything about the facts of this specific case, it nevertheless seems to me largely unobjectionable as a matter of principle to consider whether Vonage has violated Texas' general deceptive practices law.
I'm not sure why the end result of such a lawsuit, implicitly or otherwise, necessarily would lead to a mandate that Vonage adopt particular functionality, as opposed to a change in advertising and promotional materials if it is determined it has failed to comply with the deceptive practices law. It even seems to me that it may be easier to argue for market-oriented solutions to the E-911 question when there is a consumer protection regime of general applicability in play and as a backdrop.