The Greek polls have opened, and will stay open until around 4pm British time, with the first exit polls being released around 6:30. Although opinion polling isn't allowed in the country in the two weeks leading up to the election, various organisations have been conducting their own private polls, many of which reportedly  point to the conservative New Democrats winning by a hair's breadth.
There are still a number of undecideds in the Greek electorate, however, and analysis has been devoted to trying to determine what is likely to swing them. Some jokingly suggest that the results of Saturday's football match against Russia (which Greece won in a surprise 1-0 result) may lead to the Greeks feeling more emboldened to elect a candidate who will stand up to Europe; others that it may make them feel better about the whole situation and just want to play along.
Something which may have a real effect on the polls was suggested by Business Insider's Joe Weisenthal: taxes. Owing to the backwards nature of the Greek tax system (which still involves paying much of the bills in person with cash), the caretaker government hasn't levied any taxes in the run-up to the election. But they are widely expected to be raised in the next couple of days, which means many Greeks are heading to their accountants :
Okay, so in the past several days people have begun preparing their post-election taxes, and they've been hit with sticker shock. The new austerity reforms have seen some major increases in tax bills for the average Greek... sometimes to the tune of 300-400 per cent, according to one person familiar with the intricacies of it all.
This has got people particularly angry, and it could be this trend which causes people at the last second to turn away from [the leader of the New Democrats, Antonis] Samaras with disgust, and vote for [the leader of the SYRIZA, Alexis] Tsipras.
Many in the European establishment see the election of Tsipras as the worst case scenario for Greece, fearing that it will lead him and Angela Merkel to enter into a game of chicken  which will result in Greece being ejected from the euro. But the Financial Times is reporting that one even worse outcome may be about to occur; a hung parliament :
Private opinion polls showed that none of the parties would win a parliamentary majority. The centre-right New Democracy party had a three-point lead over the radical left Syriza coalition, but neither party would capture even 30 per cent of the vote, according to two private polls seen by the FT. . .
A delay in forming a coalition, or in the worst case, a recourse to a third election if negotiations fail, could cause Greek public finances to collapse. Officials at the finance ministry said last week that unless a delayed €1bn tranche of EU-IMF funding is paid, funds to pay pensions and public sector wages would be exhausted by July 20.
The World Bank's outgoing head, Rober Zoellick, has told the Observer  that Europe is one step away from a "Lehmans moment", but much of his criticism was focused on the deleterious effects of uncertainty in Europe on developing nations. That uncertainty will either be cleared up, or magnified greatly, by events today.