Pretty much what patches said. The ones that stay are mostly Albanian and Macedonians, for geographic reasons mostly.
A clarification on government formation:
If no party wins outright, as is expected, the president gives the biggest group - expected to be New Democracy - three days to form a government. If it fails, the second biggest party would be given a chance, and then the next one, until all parties have had a go.
If they all fail, new elections would be called in about 20-25 days.
This means that if government is not formed after this election, the next one would take place somewhere between June 23-38.
In other words, if the biggest group did not gain enough votes to legitimately rule the country, then the president decrees that the biggest group must become the government. Autocracy much?
What's the criteria for "forming a government"? Does the president just look around and say, "oh, we have a government now! Good job, New Democracy! Now enjoy your illegally gained power."
Or, does he give the first group (New Democracy) first dibs on forming a coalition government, while the other groups are prohibited from doing so?