Governments arent necessarily againt Bitcoin, it's the feds that dont like it. A government owned by feds will despise Bitcoin, but the biggest law-passer in the world is still extremely slow to act. Bitcoin is no more legal or illegal than gold, and no law ever stopped piracy, so why bother passing one? They're more focused on controlling the Internet; if they accomplish this (and they're always trying) then you can expect a whole slew of prosecuting to begin. America would love to tax Bitcoin, and since every transaction is public, they could potentially force users to declare their identities so they can be properly taxed. It would be impossible to avoid taxation at that point, unless you resort to trading cash in person again.
Well not true. You can hold gold in you hands, you can dig for it, its is not made of 0 and 1, it is a currecy used is so many ways. MMF uses it also, World Bank and so on... Bitcoin is worth less then 1 billion $ ( atm ) so thats not much "money" to start with. You cant tax something that is virtual, thats not like money on PP ( $, punds, yen, and so on ), and since you cant control it its not good for any country.