Moving to Microsoft Exchange Server 2010 should not be a nightmare and Microsoft has released a number of tools to help you identify any issues in your current environment that could cause you headaches during your move.
Tool Number 1: Exchange Deployment Assistant
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.
Tool Number 2: Exchange Pre-Deployment Analyzer
You can use the Exchange Pre-Deployment Analyzer to perform an overall topology readiness scan of your environment. When you run the Exchange Pre-Deployment Analyzer, it provides a detailed report that will alert you if there are any issues within your organization, which could prevent you from deploying Exchange 2010. For example, the Exchange Pre-Deployment Analyzer will notify you if you haven't deployed the minimum required Exchange service pack on all your existing Exchange servers.
Tool Number 3: (well not really a tool) Microsoft Exchange Server 2010 Install Guide Templates
You can use these templates as a starting point for formally documenting your organization's server build procedures for servers that will have Microsoft Exchange Server 2010 server roles installed on them. Templates are provided for the Client Access, Hub Transport, and Mailbox server roles, plus a template for the Mailbox role configured for a database availability group.