I don't see what's wrong with this? VS is a developer tool to create solutions with MS products and Open Source products are interoperable by design so what's the fuss?
Case in point, I work for a company heavily involved in open source development with key Apache projects. But that didn't stop us from developing a project to integrate an open source tool (Apache Maven) for .NET development. It's available at Codeplex - the open source development portal for MS at http://www.codeplex.com/npanday
Also its done primarily in the Philippines. So stop speculating and just do what you can do to change the world.