If you're looking for a good overview with which things you have to deal as a MCMS 2002 developer when you want to start developing with SharePoint 2007, the following article is a must read!
SharePoint Server 2007 for MCMS 2002 Developers
Explore Microsoft Office SharePoint Server 2007, which merges functionality of Microsoft Content Management Server (MCMS) 2002 and Microsoft Office SharePoint Portal Server 2003 with new functionality to create one integrated set of technologies built on Microsoft Windows SharePoint Services (version 3).