Two orders of magnitude (which isn't all that "many") would make that 2,400 people working on the Visual Studio shell. Although its likely there are many more than pictured, I can't imagine it being thousands.
I worked on VS2010 on a team that provided functionality delivered inside the shell. It's very hard to say how many people actually work on VS as a whole, but it's a whole heck of a lot of people. Pretty much all of DevDiv has at least something to do with VS. Then there are teams outside of DevDiv that also contribute (such as mine, I was on a SQL Server team). I do agree the team responsible for the shell itself is probably not too big.
>I do agree the team responsible for the shell itself is probably not too big.
The shell team has 5 developers (6 now, as a new one started a few weeks ago). 5 QA members and 2 PMs (actually, I think 3 now, one just started in Haifa, I haven't met him yet and don't know too much of what he is working on).
What each team is specifically responsible for is hard to say as it can change when re-orgs happen. Though the shell team owns a lot of the core functionality of VS like the windowing system, the command system, and some common windows (like the solution explorer, the output window, the error list/task list, the toolbox, probably a slew of others I don't know about :))
