Chad Myers points out a fluent way of configuring NHibernate on his blog. Nice!

He explains that this is possible in the current release:

MsSqlConfiguration
   .MsSql2005
   .ConnectionString.Is("Server=(local);Database=dbname;uid=user;pwd=password");
   .Configure( nhibConfig );

Apparently it's already in the Fluent NHibernate trunk.