Well, any Government claiming to be democratic will have a hard time to outlaw the connection of numeric values in form of in-/and outputs to cryptographic Keys and spread of this linking through a p2p network... or however you would describe what Bitcoin actually is.
Better describe it good or have the risk of outlawing Skype right with it.
I don't see any foundation on that Bitcoin could be outlawed.
Maybe outlaw the exchange and the Use as a currency? I don't know the laws for the US, but the laws for Germany (and therefore probably the EU as they Standardize everything) state that it's legal to accept (nearly) everything as payment as long as you pay tax in Euro.
The German Bank Regulation has stated:
Units of Value intended to function as currency that can be exchanged against real benefits, goods or services or that f.e. Bitcoin, can be created in computer networks .....(snip).... a permission to create and use this Units of Value as currency is not required.
SourceSo trade is (yet) legal, and I see now way how they could outlaw it without making basically every exchange that has no € in it illegal. And that would create a Shitstorm.
But what is about the exchanges?
The G. Bank regulation states further
If this Units become a commercial subject themselves the business has to qualify as Bank account as for § 1 Abs. 1 Satz 2 Nrn. 4 or 10 KWG or Financial Service Provider as for § 1 Abs. 1a Satz 2 Nrn. 1 - 4 KWG and operates under reservation of § 32 Abs. 1 KWG
So damn it, exchanges will have to qualify as financial service provider in order to operate.
Guess what, Bitcoin-Central already has that.
I think in the future there will be more regulation on how to acquire bitcoins and how to use them.
And just with cash today:
Some will follow all of them
Most will follow them only where they think they might get caught.
Some will follow nearly none of them.
There might be a crash though, when exchanges being closed amass and account frozen in the transition phase from everyone can make an exchange to all exchanges require to be licensed.