The department of commerce wants to create such an identity system. I'm not sure I like the idea, but it would be "single sign on". I think it is a safe bet that their intention is to eventually make it mandatory, and they have the "ownership", presumed trust, and longevity, not to mention the ability to pass laws "encouraging" adoption.
Putting it in the hands of the government actually fails the trust requirement. Trust is not a binary "this entity is trustworthy", trust is a set of relationships between two entities, and not everyone will trust the US Government, nor will everybody be trusted by the US Government. Even in a perfect world with a perfect US Government, that is the correct answer; not everyone is under US jurisdiction, after all, so we don't even need to get into the political issues. If made mandatory (and the only option), this is a critical failure on the trust front. It can't work, you can't tie your login system to only the US login system, and if you have to have other login systems, US citizens will be able to use those too.
I can already see the early adopters: Russia, China, France, Germany...
Even if you do it so that the actual data stores are separate and you manage to keep the APIs the same, lots of countries will have huge issues with adopting U.S. policies.
No, the Department of Commerce wants to help create a standard. It's a damn hard task, but even harder when the net's FUD is the feds want to create an identity system. No, no they don't. And their process is pretty great. But they will fail, in no small part due to FUD, and we'll all be using Facebook Login Plus soon and wondering why we never got an open standard.
There are probably better news reports out there, but this is what I found with a quick google: http://www.commerce.gov/news/press-releases/2011/01/07/us-co...