Office develoepr tools are available with Microsoft Visual Studio. Also the built-in macro editor helps us to extend Office. The office products may be not so important in the age of web and cloud based free solutions like Google Docs. But on the other hand, corporate offices still relies on the office programs.
Windows operating systems and Microsoft office are the two best divisions of Microsoft. Office also has online version where you can create documents for free and store in Sky Drive. In my experience, none of the mail clients can compete well with Microsoft Office Outlook it's one of the best email client solution. However, the online mail services like Gmail and hot mail giving better flexibility like conversational view, almost unlimited storage faster interface etc. Ultimately office works with any webservices which supports standard message protocols. But it's not really in the age of death. Google docs is a true competitor for Microsoft.