During the Heroes Happen Here events, I received a fair amount of questions regarding the combine use of VS 2005 and VS 2008 in development teams. Since VS 2008 allow the targeting of 2.0 framework, what happens if you open and save the solution with 2008 to the 2005 users. I found this blog post from DJ Park, program manager on the VS team, that does a great job at explaining the differences and how you could use both. Let me know if it helps.