According to the news at mbl.is the eruption in Grímsfjall volcano did end at 07:00 UTC on the 28. May 2011. But that was when the last harmonic tremor was seen on Icelandic Met Office SIL stations.
There is an lot of volcano as in the area around Grímsfjall volcano. That means it is going to blow easy with the wind in the dry summer.
According to GPS data from Icelandic Met Office. It seems that inflation has started at Grímsfjall volcano again. But it can be assumed that it is going to take several years until next eruption. But if that is going happen we just have too see.
Morgunblaðið news about the end of the eruption.