What is going on with Greek debt right now?

From Paul Mason, here is the summary bit:

So a worst-case scenario under a Syriza victory is: short-term repayment crisis, botched negotiations with the EU, social upheaval, capital flight and default.

A best-case scenario – for Syriza – would see its EU allies force a long-term debt deal, but it would have to ride out and tactically manoeuvre on the 2015 debt repayments, as suggested above, and there would still be massive social upheaval.

Most of the post is more detailed, and considers possible debt scenarios, clear and useful throughout, a good way to get up to speed on the Greek situation again.