According to the news the glacier flood from Grímsvötn is subsiding and is expected to be over in the next two to three days. At the same time the harmonic tremor that started at 3rd of November 2010 is also subsiding. No clear reason is for the harmonic tremors.
Currently there is nothing that indicates that a eruption is about to start in Grímsfjalli. But that can change with a short notice, as Grímsfjall sometimes does not give a long warning before it starts erupting.
Icelandic News. Please use Google Translate.
Flood waning, Iceland volcano eruption less likely (washingtonpost.com) – Thanks to Erik for this news.