I was just looking at the access logs on two servers, and googlebot seems to have not made any requests since 2pm UK time (to make it easy, thats just over 8hrs before this post time). From just one site on one of the servers it has been requesting on average 3 pages per minute steadily so far this month, so it is a marked stop.
I'm not worried about it stopping, I was just wondering if this was a widespread hault and, if so, whether it could be a sign of something happening behind the scenes.