That is a question I recently asked myself. I'm a bit embarrassed to admit that I am unable to provide a solid answer. I know some of the high level bullet points about what's new in IIS7, but I really need to spend some time dissecting the things developers should know about Windows Server 2008. Turns out there's a nice little study guide titled Welcome to the Windows Server 2008 Developer Story over at MSDN. That is where I will start.