Google was still displaying Adsense ads on my websites, but I was unable to log in and get reports.

When I tried logging in at 4.50pm Australian time, the notice on their page said they were temporarily down for system maintenance but would be up again at approx. 12:00 am PST (US time) on Feb 26.

It's up and working fine now. But we'll see what happens over the next week, eh?