While making election predictions is not the focus of this website, making political calls is something that I would consider to be in my core competency, and my guess is that the people of Greece will be giving a plurality of votes to the anti-austerity party, SYRIZA. My prediction is that they will receive 22-25% of the vote and with the 1/6th seat bonus that the top party gets in the legislature, this will put them at 39-42% of the seats in the Greek parliament.
This will require them to make a coalition with one of the other parties in order to have any hope of forming government. In this respect, 39% is a lot different than a 42% result – 39% will require them to form government with the socialist PASOK, but 42% will give them more freedom to likely work with one the other minor parties and strike up the best deal with them from a position of negotiating strength. If they cannot form government, the other parties are sure to not form government and there will be yet another election.
What this means in the macroeconomic scope is that there will be yet further uncertainty in Greece and this will translate into continued focus on Greek domestic impact on the entire EU.