The world's worst portmanteau is back: Grexit.That's short for "Greek exit," as in Greece leaving the euro. And it's once again a possibility now that the left-wing, anti-austerity party Syriza has won power in the latest elections. The risk, as I've said before, is that the rest of Europe is in good enough shape that Germany finally thinks it can let Greece leave, and Greece's budget is in good enough shape that it finally thinks it can leave too.