Those of you who are using Visual Studio 2010, Beta 1 have probably noticed the Dotfuscator Community edition listing in the VSTS Tools menu. Dotfuscator is made by the the developers at PreEmptive Solutions, and they have begun a blog detailing the features available in Dotfuscator, and how to use them. Here is a link to one of their first posts, and here is another post you might find interesting.
On their web site, PerEmptive says: “Dotfuscator Software Services – Community Edition is shipping within Visual Studio 2010 and it’s far more than an obfuscation tool. With our post-build, code injection platform, developers can track application and feature usage, defend against tampering, and force application expirations.”