It was bound to happen. Google is now bundling a suite of applications for corporate use. While this isn't an office suite per se -- and certainly doesn't compete directly with Microsoft Office -- it's still a foray into the corporate world.
The new suite is called Google Apps for Your Domain, and is centered around Gmail; an organization gets to give every user in its domain a Gmail address. Other applications in the suite (all web-based) include Google Calendar, Google Talk, and Google Panel (to manage user accounts, mailing lists, and the like).
Google Apps for Your Domain (AKA Gmail for Your Domain) is currently available as a limited beta test. Click here to learn more and potentially sign up.