One of the first results delivered from pattern & practices was the Application Architecture Guide, and if I remember correctly that was back in 2002 or 2003. That's a long time ago considering the speed in which .NET Framework and related technologies has progressed and also the big focus shifts in many areas like project methodolgy, DDD vs Transaction Script and other. Just before christmas pattern & practices released version 2 of this guidance (which I haven't noticed until today). I haven't been able to read it yet, but I sure will do. The first guidance had a lot of useful information and I'm sure that also the new version will be very useful.