Microsoft released a document describing their in-house upgrade from Exchange 2007 to Exchange 2010. Interesting stuff because of Microsoft’s geographical orientation, the volumes involved and Microsoft usually dogfooding their own products.
You can retrieve the document here.
On a side note, I took 70-662 today (still had to take that one). I passed, but what a dissapointment; are these exams getting easier or is that a consequence of getting more involved with the products related.