Update 6 November:

NASA IR satellite image shows pyroclastic flow and lava dome on NW flank. This dome is growing, which could herald new and possibly more violent pyroclastic flows.In the meantime, more than 160,000 people have been evacuated.

Update 5 November:

More that 100 casualties up to now. Pyroclastic flows reach the limit of the danger zone at 15 km from the crater. Eruption is the worst since the 1870's according to he Volcanology and Geological Disaster Mitigation Agency.

Several other volcanoes show increased activity. Among them Krakatoa.

Update 4 November:

Jakarta Post: Latest Merapi eruption largest yet, nearly exceeds danger zone.
Chief of Yogyakarta's Volcanic and Geological Disaster Mitigation Center, Surono, said that the latest development did not mean Merapi was by any means safe. He added that the volcano was still on the highest alert status and that residents should remain in shelters. "After observing Merapi's activity [on Wednesday], we expanded the danger zone to 15 kilometers," Surono said.

4 November:

 Six more people were killed when the volcano blasted rocks, ash and hot gas on Thursday. This brings the death toll to 44 over the last nine days.

While the volcano is clearly moving into a more violent phase, people had to be (sometimes forcibly) moved to shelters, some 9 km from the volcano. Aircraft is being directed away from the ash clouds that rise up to 6 km. The ash covered fields and towns nearly 250 km away.

Seismic data suggest that a stronger eruption is imminent. It seems that pressure inside the magma chamber is building up, which could set off devastating pyroclasic flows.