AdWordsAdvisor confirmed the issue at 8pm (EST) last night saying:
OK, yes, this is known to engineering - it's impacting a small percentage of advertisers, and folks here are hard at it to resolve, as you might well imagine.
The Google issue was then confirmed to be resolved at about 8:20pm (EST).
Microsoft adCenter had similar issues, and the first reports came yesterday morning via WebmasterWorld at about 5am (EST).
adCenterEU confirmed the issue was resolved at about 11am (EST) yesterday:
Excellent. Engineering let me know that this is now considered to be resolved - as of just a few minutes before the time you wrote, briggidere.
Again, my apology to those who were impacted. I'm glad it was brief. ;)