Expression Web 3 SP2 contains general improvements to the application and to SuperPreview. You can get a more complete description of Expression Web 3 SP2, including a list of issues that were fixed, in the Microsoft Knowledge Base article "Description of Expression Web 3 Service Pack 2."

You can install Expression Web 3 SP2 if you have either Expression Web 3 or Expression Web 3 with Service Pack 1 installed.

Expression Web 3 SP2 includes SuperPreview support for Firefox 3.6 along with improved stability when working with CSS, PHP, and PDF files.