Iceland just allowed their banks to fail, and they are doing great now. Still turning down EU membership.
Please stop comparing the equivalent of an S&L collapse to a sovereign debt default. Iceland's (and Ireland's) banks got too big for their britches. They were allowed to fail. Iceland's government compensated foreign depositors to the limit of deposit insurance guarantees. Anything beyond that, tough luck. Shareholders obviously got bupkis, much as bond holders and stock holders of Lehman and Bear Stearns got the stiff arm.
Greece's government got too big for its britches. Even if the debt were forgiven, Greece's government can't afford its regulations and handout programs. The solution is to pare regulations back and cut those programs. Do you see Greece doing that? No - its "solution" is to expand regulations and increase the size and scope of the handouts. This is why the next stop on Greece's itinerary, economically-speaking, is Egypt, without the religious strife, unless it bends to EU demands for economic reform.