Totally agree with that. If you have cash in Euros on you, just keep it. No point gambling it for Bitcoins. If, however they will go back to Drachmas, it will devalue immediately as the government will need to inflate it by issuing new money to repay debts and pay people. Then it might be worth to change into Bitcoins to retain some value and avoid -at least initial/sudden- inflation and loss of value. Tough situation anyway.
Indications are that Greece will be shifting to a dual-currency system, where both the Euro and the Drachma will be permitted. Those who have their money in the form of Euro banknotes have nothing to worry. However, all the new government payments (such as child benefit, pensions.etc) will be paid out in the form of Drachma.
for a useless currency....