From EHLO

We heard concerns from our early adoption Exchange Server 2010 customers regarding transitioning from Exchange Server 2003 and/or Exchange Server 2007 in a few key areas. One of which is the fact that you, Exchange/IT administrators, are burdened with complex migration steps (multiple firewall rules, multiple certificates, multiple external URLs/ports for clients). This complexity means there is opportunity for misconfiguration, which causes deployments to stall-not to mention a lot of frustration.

Based on this feedback and our desire to help streamline the deployment experience, we created Exchange Server 2010 Deployment Assistant which can be accessed at http://technet.microsoft.com/exdeploy2010

It allows you to create Exchange 2010 on-premises deployment instructions that are customized to your environment. The Assistant asks a small set of questions, and based on a your answers, it provides a finite set of instructions that are designed to get you up and running on Exchange 2010.  The idea is that, instead of wading through the 2000+ topics in the Exchange 2010 library, you can answer a few simple questions, and the Assistant gives you just enough customized content to do the upgrade..

More content is coming:
In this version of the Deployment Assistant, content is available for customers upgrading from Exchange 2003. Additional upgrade scenarios will be available in early 2010 (upgrading from Exchange Server 2007, or a mixed Exchange Server 2003/2007 environment for example). We will also work on the integration of cross-premise scenarios.