sklosed - 2:59 am on Mar 18, 2011 (gmt 0)
Seeing the same for our site in Australia. March 12 saw a 10% plus drop, then a partial recovery over the next two days, with a definite drop again on the 17th. Appears to be the same on the 18th.
I thought it may have been the situation in Japan but I'm not so sure now.