I worked for Microsoft in 2000-2001 in Redmond as a technical editor in the developer division. Most of the content I worked on shipped with the .NET Framework 1.0. I quit to move to Southern California and be closer to my extended family (I'm originally from Orange County). So it had been six years since I had been on the Redmond campus when I arrived to interview for my current job in February 2008. I was curious to see if the company had changed since I left in 2001. My impression has been that things haven't changed much at all.
One pervasive impression Microsoft made on me during my previous tenure is that the company had a lot of momentum. You can still see this in the emails from the company's leadership, the attitude people have toward getting their products out the door, and in the prodigious amount of new construction at the Redmond campus. When you first join the company, this momentum makes you nervous, because you wonder how you'll learn your job fast enough to be able to contribute. It feels as if the work is rushing by and you want it to slow down long enough for you to read a stack of technical books.
Another thing I noticed is that the free soft drinks are better than they used to be. They have a bigger selection (more fizzy juices and the like), and they still have some of my old favorites like chocolate milk and Cherry Coke. ;)