If you are referring to initial migration to Office 365, then I would ask that you post in the O365 forums. Either way, all are available (though the website will be a bit different since you'll have to figure out how to incorporate it using SharePoint
If you are referring to transition from BPOS-S to Office 365, then all of those transfer.
- All mail items transition from BPOS-S to O365
- All email addresses associated with your BPOS-S accounts will transfer to Office 365
- All SharePoint content will transition in the way it was in BPOS-S (minus the deprecated web parts).