In addition to last night's downtime PayPal reported some problems this morning which they claim are resolved now:
RESOLVED: This issue has been resolved at this time. We saw a complete recovery of this issue as of Jun 17, 9:00 AM PDT (Jun 17, 4:00 PM GMT). During the time of the incident, majority of API requests may have failed with error 10001 (Internal Error) and payments may not have completed. Users may also have seen "Sorry - your last action could not be completed" error message while accessing
Sent Jun 17, 10:04 AM PDT by ASR
UPDATE 1: We have begun recovery on this issue and will send out an update in the next 30 minutes or sooner if there is a change in status.
Sent Jun 17, 9:22 AM PDT by ASR
NOTIFICATION: We are currently experiencing a system issue affecting the Live PayPal Site.
Sent Jun 17, 8:45 AM PDT by ASR