I completely agree with you that governments will have huge incentive in trying to control Bitcoin. Controlling the monetary unit of a country is a very effective way for a government to finance itself. Let's hope they're as unsuccessful doing this as they have been at deterring piracy though.
I wouldn't say Bitcoin is currently deflationary...in fact, the _inflation_ rate (as measured by the amount of new BTC created as a % of circulating BTC) is ridiculously high -- eg, how many coins existed 1 year ago cf. today?
If you measure inflation by how much stuff costs, then every time the ticker goes up, bitcoin is deflating...but that's happening despite massive % increases in the coin supply...if governments tried to pull that of, their currency would lose tremendous % value.