If I were an entity such as the Federal Reserve or US Fedgov I would be extremely threatened by Bitcoin.
This is the point where your reasoning goes wrong.
The government isn't threatened by bitcoin. Why would it be? Right now it is just a nerdy internet cryptocurrency accepted by almost nobody (with the exception of sellers of black/grey market goods and services and hardcore proponents). It's main userbase scams each other on an alarming scale, and the network (mining) consists of a neverending arms race that ensures that eventually only the top x% can run it.
Lets be honest, this whole thing will collapse itself eventually....it doesnt need the governments help.
I agree that this is how government as a whole probably perceives it.
There may be a few individuals in law enforcement or even politicians who see the potential of grass-roots programmable money - but I doubt it will truly be on governments radars as a genuine threat which is worth assigning serious resources, until large scale usage in particular areas of governmental concern actually occurs.
They'll react once the volume of trade related to things like silk-road drugs, money laundering or bypassing of gambling laws is approaching billions of USD worth.
Aside from large scale operations grabbing their attention - the other thing that could prompt action would be a highly public successful extortion or kidnap ransom type of event. (The Romney tax thing came close - but it'd have to actually be something that followed through and had serious consequences financially, politically or lethally)
That sort of event aside - it would really surprise me to see them react pre-emptively against bitcoin whilst the entire Bitcoin economy is only on the order of a few hundred million USD.
I could be wrong - but I see politicians and government bodies as far more reactionary than visionary, and no public servant or politician is going to gain much advantage tackling something that their peers don't understand and that the public doesn't particularly care about. Once the horse has bolted - then they'll stir into action.
edit: The other potential trigger for governmental action could be lobbyists from particular industries (e.g payments/banking) who do understand the threat - but there again, it seems a stretch to think they'll react or be able to successfully get action unless the numbers show an existing phenomenon that is eating into profits.