We (UK-based, Wave 15 E3) also experienced severe OLK2011 issues yesterday. We have had a call open with MSPS for more than a few days and the problem became worse yesterday, so much so that we escalated from SEV B to a SEV A. That seemed to get MSPS attention finally.
We enabled Troubleshooting Logs for OLK2011 and uploaded these logs to MS. Within a short space of time the SHD was showing an issue that was being investigated. A little while longer the SHD changed to a more specific notice regarding EWS and application memory (Incident ID EX3517):
Microsoft is working to restore service for some customers served from the European region that are experiencing intermittent connectivity issues when using the Exchange Web Service (EWS). Outlook Web App and Outlook client connectivity is unaffected. Investigation determined that memory utilization and CPU consumption for EWS specific service was unexpectedly high. Exchange Online engineers are recycling the affected EWS application pools to mitigate end-user impact.
As seems to be common with MS, it is up to the customer to prove the issue is not your own but Microsoft's. You need to jump through the hoops to get the point rammed home for them to act. I am surprised there isn't a more proactive approach to what appear to be resource issues on application pools, since the majority of It departments have monitoring for their own in-house services. And even more surprised that it sounds like the rebooted a few servers.
I have my own forum post relating to our issues (http://community.office365.com/en-us/forums/153/t/192219.aspx) and it seems to be the same as has been experienced in this topic.
I would also add that enabling logging may also pick up on Synch issues relating to corrupt items. Microsoft's own solution is to 1) remove the problem folder(s) all together 2) empty Deleted Items or 3) delete the Outlook identity folder and recreate the identity. Given the shonky nature of how OLK2011 maintains its database (Database Daemon, urghh) this latter problem is regularly seen and it's a real shame that the remnants of Entourage still linger on within OLK2011..
Oh, and we're not seeing any issues today.
