There are of course 2 options. One is to go ahead with the austerity measures which will punish the poor in the country and not affect the rich that much and two default.
It is my opinion that George Papandreou will not be able to get enough support in Parliament on Tuesday and win the vote. This is because the people of Greece through PAME ( a TU movement against the cuts) will intensify the rate of protest and more pressure will be put on individual politicians who are members of the PASOK governement to either vote against or abstain, if they don't then they will live to regret their decision. So I am sure that the government will not win the vote and the austerity measures will not be imposed.
If the austerity programme does not go through then the country will be defaulting de facto. Which means that Greece will be leaving the euro and not paying back its debts. This will of course also mean that Portugal and Ireland will try and follow the example which will mean a run on the euro with severe consequences on the world economy. We are, unfortunately, at the start of a major financial disaster... I hope I am wrong.