I've been using Windsor on a Windows service for the last couple of weeks and the nastiness of its XML files quickly became a pain.
I don't tend to mind XML too much, for example I think the XML configuration option with NHibernate is pretty good, but Windsor's is just way too wordy and repetitive.
Anyway I had another look at Binsor but having to learn Boo and the DSL itself is hard enough and without IDE support (other than SharpDevelop) I thought it was too much.
Good news is it looks like there is already a fluent interface project for Windsor. You can read about it at Hammett's blog (or in this dev thread), there is also a blog entry about an approach that allows automatically registering services from an assembly. All very good and examples