Apparently while we were all looking at Hekla, Katla was secretly getting ready to go. There has been a small eruption underneath Mýrdalsjökull, the glacier Katla lies under, but it seems to be over now. The only results so far seem to be cracks in the glacier and a jökulhlaup that washed away a bridge and some parts of Ring Road 1. Some people have been evacuated, mostly from camping sites, and people near the rivers have been warned about the possibility of toxic gasses from the meltwater.
So no fear, Katla did not do the whole ash-thing - at least not this time.
EDIT: just as I posted this there were more news: Katla's calming down but there's still a lot of harmonic tremor around the area, so there's always a possibility we'll hear more about her. I'll try to keep this blog updated if something unusual happens, as always.