I don't think they will succeed, because the laws of physics will see that unsustainable enterprises wither from lack of cheap resources.

But that doesn't mean they will stop destroying everything in their opposition, not until that opposition overwhelms them, after the cost of generations of suffering.

says "This Could be the Moment for Greece to Default"

http://www.ft.com/intl/cms/s/0/26f7a326-c0d6-11e3-bd6b-00144feabdc0.html?siteedition=intl

Behind a paywall, so for those who can't get through, his logic: Greece is now running a "primary surplus", meaning that if you take out interest payments on their debt, the government is actually solvent. That means they don't actually need foreign investors to fund themselves anymore.
Another FT columnist, John Dizard, pointed out a year or two ago that once Greece goes into primary surplus, the threat of them defaulting would rise.
Munchau notes that while the default itself would doubtless be wrenching, once done, Greece would have no problem accessing the markets again to borrow, as the moment after you've defaulted is also the moment when you're least likely to have to do it again on new debt.
For the debt talked about in the OP, they will not be able to default on that nearly as easily because it's issued under English law. It's only possible on their old debt because most of it was issued under Greek law, so the terms can be changed by the Greek gov't itself. Meaning that after this, this option is going to get much harder.
For those who don't know, a Canadian economist named Mundell is the one behind the euro. I've never seen it explicitly stated by him, but most folks figure he meant it as a new version of the old gold standard, one that would do the same thing the old gold standard used to do (according to right wing folklore, by the way, not actual history: the first welfare state arose in Germany during the time of the old gold standard, and British labor unions and their new Labor Party both grew rapidly under it): discipline workers and prevent governments from being all fiscally profligate and Keynesian.
A good intro to Mundell and his logic: Robert Mundell, evil genius of the euro