Hi Jon,
We used to use bitmap effects for the title outer glow however Microsoft removed bitmap effects in .NET 4 so we were forced to move to the newer Effects they created however they never provided an outer glow replacement. We have to do multiple passes of blurs to achieve what we have now, however it isn't quite as clear as the old bitmap effects were. We have some ideas we're going to try as we continue work on the Office 2010 themes that are coming in WPF Studio 2010.2.