Implementing the Decorator pattern with Resharper is a snap.
This post shows how this is so easy with interfaces.
A few things to keep in mind, though, is when inheriting and decorating a class and you are intending to override its virtual properties, delegating property calls to the inner class (thereby leaving the real class with default values in fields).
1. Resharper by default doesn't declare 'override' on these overriden virtual members. You'll get a warning asking if you intended 'new' but not a compile-time error so members will be 'null' or default(whatever) at runtime. This can be confusing.
2. If you have used Resharper for Equals()/HashCode() generation be sure to change the base class's implementation to point not at the fields for value checking but rather the (potentially overriden) properties. That way the derived class will participate in these checks and avoid any NullReference exceptions.
Mike