Microsoft has released Service Pack 2 (SP2) for Expression Web 2, containg significant fixes and improvements in support for jQuery, image thumbnails in the Folder List panel, a new Snippets panel and more.
Key Improvements:

• jQuery support – IntelliSense has been added for jQuery. In addition to the jQuery functions themselves; it also includes the ability to continuously chain jQuery function calls and obtain IntelliSense.
• New Snippets Panel – the Snippets panel provides the following improvements:
• Ability to create folders to categorize your snippets.
• Ability to create wrap snippets- now you can use to surround text you select in Code view.
• Includes a large number of new sample snippets across several categories.
• Ability to quickly search the Snippets panel to find snippets by name, description, and the code of the snippet itself.
• Code view now provides context-sensitive comment and uncomment functionality for HTML, CSS, PHP, and JavaScript.
• Code View – now uses the popular Consolas font by default. Color and syntax highlighting in Code view have also been improved.

You can get a more complete description of Expression Web 4 SP2, including a list of issues that are fixed, in the Microsoft Knowledge Base article entitled “Description of the Microsoft Expression Web 4 Service Pack 2.”

Expression Web 4 SP2 RTM is Build 4.0.1303.0, you can determine SP2 by clicking Help menu, About Microsoft Expression Web.
Download: Expression Web 4 SP2 RTM