There is a great article on MSDN about building distributed applications in .NET. It's a six parter, mainly focused on using a service-oriented architecture. It is definitely not light reading, especially considering it is around 228 printed pages long. From what I can tell, it goes into great detail when dealing with the architecture of the system. The article even covers issues with legacy systems and application maintenance/deployment.
I will try to post a little better review of the article once I actually am able to read it. I imagine that 228 pages dealing with architecture might take a while to get through. I believe from the development methodology used, it is much more “traditional” (i.e. not XP). However, for any XP developers out there, I think this article is still a must read. Perhaps I am going to rub some developers the wrong way here, but I believe that in order to be a successful XP developer you need to have a solid understanding of architecture as a whole, along with refactoring and design patterns.