Some more detail about the schema of the databases would be nice.
Also, how about a section about moving hardware platforms, I know this has been a discussion topic before and the DR method is the best choice but as this is certainly something which everyone will have to do every so often, why not give a recomended method.
Some specifics about MAPI and the DLL issues that we've all seen in the past.
That's all for now....I'm currently reading the V6 docs so may have some more comments