Administrative e-mail tools
Even though Exchange 365 is hosted in the cloud, rather than on your company's server, you still get a full suite of administrative tools. You can easily add new Outlook users, either singly or in bulk (via .CSV files), determine whether users get administrative rights, and so on.
There are also tools for migrating in-boxes from a company's server-based version of Exchange to the Office 365 cloud-based version. These tools won't work for people who have been using Outlook in concert with POP3-based mail, though. There is a migration tool for IMAP accounts, although that requires a bit of extra work.
You'll also find a variety of more sophisticated tools as well -- for example, you can set group permissions for performing tasks such as allowing people to search across multiple mailboxes. In short, you get the kind of administrative tools you expect with Exchange, even though you don't host Exchange yourself.
Unfortunately, this is also one of many examples of the poor overall integration in the Office 365 beta. When you're on the pages for managing Exchange, there's no navigation to any other part of Office 365 -- essentially you're in a silo that appears to be a dead end. You have to navigate back to Outlook, and from there use site-wide navigation. This is a problem that appears time and again throughout the suite.
Office 365 also offers a hosted version of SharePoint, which allows you to build team sites where everyone in your organization can collaborate on documents and share a common document library.
Creating and designing a new team site is surprisingly easy. You choose a design, theme color and so on, and then add elements such as images, tables and document libraries. Adding documents to a team site is exceptionally easy: Click an Add Document button, choose the file you want to upload, and your work is done.
Office 365 gives you a great deal of control over your team sites, far more than most organizations will ever use. You can, for example, set up groups with specific permissions, and then assign people to those groups. You can customize document permissions to an extremely fine degree -- for example, giving some people read-only access, others full control, others only the ability to contribute but not make edits, and so on. You control who can access the site and who can't.
In short, you get all the usual SharePoint tools, including the ability to share documents with those outside your organization. Team sites also include version control functionality, so documents can be checked into and out of libraries, to ensure that people can't overwrite one another's work.
Office Web Apps
Microsoft has forged links between Microsoft Office and team sites in Office 365. When you click on a document in a team site, you can open and edit it in Office, and then save it back to the team site. In addition, if you use Microsoft Office Professional Plus, which includes Microsoft SharePoint Workspace 2010, you can get access to team sites and their document libraries when you're offline by syncing to them when you're online, using them offline, and then resyncing when you're back online again. And you can also publish Access databases to SharePoint Online and allow people to get access to those databases from a Web browser.
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.