Iceland Review seems to think the chances of flight disruption are
slim with the change in ash characteristics :

http://icelandreview.com

The ash being emitted is much coarser than it was during the first
days of the eruption. The fine particles that caused the most
disturbances in the upper atmosphere, and thus disrupted flights, have
disappeared.

Oddsson was on a team of scientists who traveled up to
Eyjafjallajökull on Wednesday to collect samples from the ash which is
currently being emitted from the crater.

The geologists said they walked into a rain of volcanic debris. “We
didn’t go so far that we were at risk of being hit by boulders, only
smaller rocks and grains. You could feel them hit your shoulder.”

For the most part, domestic and international flight schedules in
Iceland returned to normal yesterday after the airports in Reykjavík
and Keflavík reopened. “It is running like a well-oiled machine,”
commented Hjördís Gudmundsdóttir, information office at ISAVIA.

It doesn’t appear as if the ash from Eyjafjallajökull will disrupt
flights in the coming days. Yet there is nothing to indicate that the
eruption is coming to an end; magma flow and the size of the volcanic
cloud is about the same as it has been in the past days, ruv.is
reports.