The other change you'll notice right away is that Microsoft has tweaked the interface yet again. In 2008, the company added the Elements Gallery, a row of tabs beneath the Toolbars that that was supposed to make it easier for users to find hidden features. While the gallery did bring some commands to the surface, they usually were not the ones users needed most often.
The new suite takes the idea further, adopting a Ribbon similar to the one in Windows Office. The Ribbon, also located beneath the Toolbars, takes the commands people tend to use most often and groups them logically into a sort of fat, intelligently constructed toolbar. For example, formatting features that were previously located in a floating palette are now at the top of the window, which makes them much easier to find and use.
You can customize the Ribbon somewhat by deleting tabs or groups you don't want and reordering the rest. Unfortunately, you can't actually edit the commands that are available in each group, which will feel like a restriction to those of us who are used to customizing toolbars.
However, the Ribbon is context-aware. For example, if you insert a table in Word, a new tab immediately appears in the Ribbon offering table formatting features. It's an intelligent use of screen real estate -- and if you don't like it, you can just hide the Ribbon entirely.
It's not all speed and interface changes, though. Each program gets some valuable new features, including some new image-editing tools, and the suite as a whole gets a brand-new component: Outlook.
Office 2008 came with Entourage, an integrated e-mail client, contact manager and calendar application. Office 2011 Home & Business Edition replaces Entourage with Outlook, which handles the same tasks but offers more compatibility with Windows Outlook -- a welcome development for Mac users working in Windows-dominated corporate environments. For example, Windows PC users can create a .PST archive of all their data and bring it into Outlook on the Mac. (You can also import Mac data from Apple Mail, Eudora or Entourage, as well as contacts from a text file.)
However, Outlook doesn't play as well in the other direction. You can export an Outlook for Mac (.OLM) data file with mail, tasks, contacts or calendar items. But you can't export a .PST file, nor can the Windows version of Outlook import a .OLM file, which means the compatibility really only works one way. Similarly, Google's tool for syncing its Calendar with Outlook (Google Calendar Sync) works only with Windows Outlook.