While there may certainly be instability this week as a result of the ongoing financial crisis in Greece, the more interesting observation is the number of market technicians and others that are saying that Greece is the tipping point and that the market will head toward correction as a result.
As intermediate range investors there simply is not enough confirmation that anything of substance is going to happen right now. The S&P futures are down about 1.2% as of right now (9:15pm ET) and one could assume that tomorrow will be a down day.
Interestingly, the worst of all of the options is that the EU caves to the Greeks. Let them leave the EU, take the pain, and contain the damage. The markets will rise suddenly if there is a deal. But it rewards, once again, bad behavior.
I will post again, daily if need be, should the model or circumstances change.