@Bass: This is quite a small number, especially when you consider that Microsoft usually triage a project, with x amount working on release A, and y amount working on release B., which is how they could get to Silverlight 5 in 2 years. If Microsoft invest in a project that used 20 people, any small to medium enterprise can come along and compete. Most software now is about amassing a huge amount of functionality that it becomes too costly for your competitor to create a rival product, they have to think big.

Pretty much anything written in .NET and Java can be copied easily by a competitor, which is why the software world is fraught with failed projects.