Same problems as everyone else on my Win7 PC with OL 2007. Duplicated events, alarms, tasks, plus hundreds of events that didn't sync properly and that I wasn't about to debug one by one. Also, iCloud created a bunch of other calendars in Outlook, some with only 1 event in them.
I had been syncing my calendar with Google and was able to restore from there. I didn't see any errors in the contacts sync so I exported the iCloud contacts and imported them into my main contacts list. I was able to copy my tasks from the iCloud list into the main tasks list. I may have lost the completed ones but they're not important.
I've turned off the iCloud sync of contacts, tasks, and calendar and removed the iCloud add-ins from Outlook, but I can't delete the iCloud contacts or calendar files from within Outlook. When I try to delete the contacts file it gives me a permission error (I haven't tried just deleting the contacts themselves yet). The Delete command is grayed out for the calendar (when I tried deleting the celandar events I wound up deleting my main calendar as well, so I'm reluctant to go that route again). I was able to delete the iCloud tasks file.
So, anyone know how to get rid of the iCliud contacts and calendar files? (I scanned this thread but maybe I missed it.) I haven't tried deleting iCloud from my PC -- I still have it set to sync bookmarks and photos.