10,000 people joined Microsoft this year while three notable people (Scoble, Niall, Gundotra)left to pursue other interests. Techmeme is buzzing about Niall Kennedy's announcement that he is leaving to start his own company. Good luck to Niall! He is a great young guy and has a bright future ahead of him. Niall joined Microsoft in April and is leaving August 18th, so he really didn't give it much of a chance. But I understand the burning desire to do a startup...and do it fast before someone else does.
While I know all three of these guys and have a lot of respect for them, Microsoft will do just fine without them. There are 70,000 talented people at Microsoft. They wouldn't miss me if I left either. In fact, Bill Gates could leave and Microsoft wouldn't skip a beat. That is how strong and deep the team at Microsoft is today. Note, Bill hasn't left yet. He just announced that he will be leaving his day to day role in two years to devote full time to his charitable foundation.
I have worked on the management team of five startups, notably AltaVista, Napster, and Groove Networks. It was a blast! Working for Microsoft is a blast too. I love my job. Working with VCs and startups to build partnerships with Microsoft is what I love to do. On the other hand, if I was stuck in the bowels of a product group in Redmond and couldn't bring my ideas to fruition quickly...I would probably move on too.
Microsoft alumni have spawned lots of startups. It is a beautiful thing.