This post demonstrates how to configure this: http://atombrenner.blogspot.com/2010/07/how-to-change-resharper-naming-style.html
UPDATE: The Machine.Specifications testing framework extends ReSharper to allow for custom naming styles for the tests/specs. Very cool; wish other frameworks did likewise. http://lostechies.com/derekgreer/2010/02/11/resharper-naming-style-for-machine-specifications/