See here for details:
SharePoint Online will now have BCS! The lack of BCS is a real problem for many people wanting to try out the “cloud” and especially when the only custom code is via a sandbox solution. But sadly, this is for Enterprise (“E” plan) subscriptions only.
Windows Phone 7 "Mango” (the latest update to Windows 7 Phone) connectivity!
This gives access to Windows 7 Phones to SharePoint lists and libraries. This is for both “E” and “P” plans.
Recycle Bin: deleted site self-recovery
SharePoint 2010 got this with Service Pack 1. Now SharePoint online users can “undelete” a site!
Browser support for Internet Explorer 9
Now who would of thunk of that?
Browser support: Chrome