One of the things that I find interesting about working at Microsoft is that it's not just a company, but with tens of thousands of employees spread across countless different buildings, locations, disciplines, and products, it's its own miniature world. It's big enough that I still find myself referring to the company I work for as "they" and not "we."
Originally, I assumed that a company as big and structured as Microsoft would have no grapevine: that such a thing would somehow be extinguished. Not so. Rumor runs rampant at Microsoft, as I imagine it would at any company, and I think that I understand why. With that many employees, if you give out too much information regarding the future of a given product (in particular, I'm talking about Longhorn, the next version of Windows), then it's going to slip out to the public at some point. So, a lot of important stuff is kept under wraps. As a developer on FrontPage, I'm privy to a lot more about Longhorn than your average Microsoft employee, but the long-term business strategies, goals, and so forth are kept as closely-guarded secrets, with little bits of information sprinkled into our big fish tank on an irregular basis, usually coinciding with public announcements from the executives.
As much as I'm sure they'd like to minimize it, this causes a lot of rumors and discussion amongst the employees, with each person "sure" that they know what's really going on. The difference is not that employees automatically assume the best, which is definitely not the case, or that their opinions are generally based more on fact than those of people outside the company, but more that everyone feels like their opinion is important since their stock value depends on it (which is, of course, true to a certain degree). All in all, it's pretty entertaining to hear all of the different bits of news about Longhorn and other big strategic products, even though it's usually not much more than we release to the public. It's kind of weird that at any given time I am not much more sure about where a product is headed than the rest of the world, but it's still a fascinating perspective for someone who has always been interested in the business of shipping software.