Recently Schwieb wrote about what we are doing with Messenger on the Mac. In his post he makes this significant comparison:
The MacBU is a medium-sized group at Microsoft (at least from my perspective) but compared to either the Win Office team or the various incarnations of the Messenger app on the Windows platform, we’re actually pretty small. The MacBU has a grand total of 52 developers (including leads and managers). A quick query across Win Office shows roughly 550 developers, meaning they are over 10x larger than we are. Yet they own only Office; we own and produce Office, Messenger, RDC and Virtual PC. Because these products are mostly in active development simultaneously, we spread our 50+ developers across these products and thus have relatively small teams. To make our numbers feel even smaller, we’re often doing maintenance work (or even feature work!) on older releases of our software.
This size differential does make things more difficult, but I see our small size as our biggest advantage. The small team size also self selects the kind of people that work in MacBU. If you can't "own" lots of code, deal with massive scale and quickly focus on what is critical, you probably will not last long on the team. There are other great advantages of a small teams of course, Personally I love the challenge and how it drives one to be both tactically deep, and yet very much a generalist, as someone else has said, "specialization is for insects." ;-)