One major shift from SharePoint on-premise to SharePoint via Office 365 from an Administrators point of view is that you now don’t get a chance to test/evaluate enhancements and the impact they will have on your users / applications that you have built on top of SharePoint. With SharePoint on-premise you could always apply the SharePoint Cumulative Update or Service Pack in a test environment and check that all your applications/customisation still work and identify any areas that you may need to train users or modify business processes to ensure a smooth upgrade.
Enter Office 365 and SharePoint online.
You now don’t get a chance to see and test the changes/enhancements until they appear on your live site. This could leave you doing a mad scramble to ensure your applications and users can continue to work smoothly.
Microsoft have launched a Wiki site dedicated to keeping the public informed of upcoming enhancements and changes to both the Enterprise and Professional Office 365 plans. While this is still a long way from providing the public with a “test” version of their Office 365 environment with the update applied, it is a solid step in the right direction.