The EDA is a very handy reference for deploying Exchange Server under different scenarios such as on-premise, hybrid, and cloud.
After choosing your scenario you’ll be prompted with a series of questions. Your answers to the questions are then used to produce a set of instructions for you to follow for your deployment.
At the time of this writing there are no instructions for upgrading to Exchange 2013 from 2007 or 2010, because the required CU1 for Exchange 2013 has not been released. Microsoft promises to release the information when CU1 is made available to the public.
The instructions produced by the EDA are quite useful though they are not highly detailed. Generally they deal with the core process and leave a lot of the detail to the rest of TechNet or up to the customer to decide (eg, Microsoft is not going to tell you which backup product to use and how to deploy it). Even still it is a good reference for customers to make use of.