Hi,
I have developed a Addin for Visual Studio 2005 and NHibernate.
Tool name is NHibernate Helper BETA.
Currently only support C# but next versions will be support other languages.

Here is an article about tool,
http://www.codeproject.com/useritems/NHibernate_Helper_Kit.asp

Also you can download Addin from here,
http://www.avvamobile.com/downloads/NHibernateHelperBETAsetup.zip

Unfortunatelly, there is no help documentation now, but i'm writing to share it.
We can discuss it here, about negatives, positives, ideas, request for the next release version.

This version,
- Only support C# and visual studio 2005. Not for vb.net and Visual Studio 2003. But i'll develop this properties next version.
- Just helps you to create mapping xml files and persistent classes. Next versions will have more ability.

thnx for interest.