According to Microsoft, you should be able to use Office Web Apps for reading, editing and creating documents on team sites, and you should be able to allow several people to work collaboratively on the same document simultaneously. I was unable to get that to work on my test machines. However, this may have been an anomaly on my part.

Office 365's flawed integration is especially evident in SharePoint. Once you enter SharePoint, you frequently lose navigation to the rest of Office 365 -- you appear to be in SharePoint alone. Even navigating to different parts of SharePoint itself is confusing, because you'll often have to use your browser's back button rather than SharePoint-specific navigation.

Office 365 includes tools for building Web sites, and this is very clearly the weak link in the chain.

If you use Office 365 for e-mail, SharePoint and other services, you also have to use Office 365's built-in tools for building and managing your Web site. Why? Because when you port your domain over to Office 365, Microsoft hosts both your Web site and your e-mail. Office 365 doesn't include a feature that simply lets you post your own HTML and Web-based applications to a Web server.