According to recent pictures and from Rúv News it appears that both Skaftárkatlar cauldrons are full of water at the moment. They might burst at any moment and create glacier flood, the right cauldron has not flooded for the past three years according to Rúv News, while the left cauldron flooded last year. When they might flood is impossible to know, but it is expected to happen in next days to weeks.
Update 1: Icelandic Meteorological Office has now declared that Skaftárhlaup glacier flood is going to happen soon. A glacier flood can start at any time without warning. The risk comes from gases in the water, along with the floodwater it self as it can reach up to 1500 m3 at peaks levels. There is also a risk the flood might go into new rivers and those rivers has bridges that might not be able withstand such glacier flood.
Details in Rúv News
Mikið vatn í eystri Skaftárkatli (Rúv.is, pictures)
Video of the Skaftárkatlar cauldrons in Vatnajökull glacier.
Skaftárhlaup vofir yfir og skapar hættu (Rúv.is, Icelandic)
Information in Icelandic from Icelandic Meteorological Office
Yfirvofandi Skaftárhlaup og möguleikar á hlaupi í Hverfisfljóti (vedur.is, Icelandic)
Blog post updated at 18:04 UTC on 14-August-2013.
Blog post updated at 19:04 UTC on 14-August-2013.