For Outlook you can be confident that your data will be available.

– Deleted items are recoverable up to 14 days old.
– Corrupt items are recoverable up to 14 days old. The newest recovered item may be at least one business day old.
– Deleted or corrupted mailboxes or any other disaster recovery will attempt to recover a mailbox up to 14 or 30 days after the problem occurred, the data may be at least one business day old.

Now that you’re aware of this you can determine your own backup strategy. The most important thing is that Deleted and Corrupt items are recoverable up to 14 days old. This means for any item older than 14 days backup/restore is up to yourself. I choose to adjust my Auto-archive settings to archive every 14 days, and make a regular backup of the archive files.

For SharePoint things are quite different, just look at this:

– Items deleted by mistake will go through the regular Recycle Bin process, this gives you 60 days to recover a deleted item. If versioning is enabled you can also restore previous versions of documents.
– If the SharePoint site is deleted by mistake or is corrupted recovery is not supported
– In case of disaster recovery MS will attempt to recover a SharePoint site up to 14 days after a disaster. The service may take six business days to be completed. The newest recovered item may be at least seven business days old.

http://www.microsoft.com/online/help/en-us/bpos/html/7b8f6b68-625d-4f45-98d8-b178c1f3f27d.htm

Sign up for a RISK FREE trial of Microsoft Online Services (no credit card required/no committment necessary) – Trial includes 20 user trial account of SharePoint Online, Exchange Online, Live Office Meeting and Office Communications Online