Regulation will be an umbrella covering all crypto-currencies.
Governments are regulating decentralized virtual currencies. Every FinCEN regulation which applies to entities exchanging Bitcoins equally applies to all current and future altcoins.
If the anonymity of cryptocurrencies become an obstacle to legally use it, it will be be sacrificed. Some freshly designed BigBrotherCoin can enforce identity disclosure to government but not to general public. Bitcoin can't.
The anonymity of Bitcoin makes it perfect tool for tax evasion. Some freshly designed TaxCoin can embed end enforce VAT rules, Bitcoin can't.
Bitcoin is open to everyone without limitations. Some
SecessionRegionalCoin can be limited to only preapproved merchants and miners, Bitcoin can't.
Governments regulate economy via money supply, using banks as a proxy. Some BanksterCoin can implement fractional reserve rules, Bitcoin can't.