There is a new release of NHibernate available, download it now. It contains a host of great new features, like support for Dependency Injection for entities using an inversion of control container of your choosing. There is also a new ANTLR based HQL parser that has allowed for some HQL improvements, like the with clause. The new ANTLR based HQL parser is also central to the forthcoming LINQ support and is the result of some great work by Steve Strong and Fabio.
This release also includes the long sought after support for executable bulk queries. This is a feature that the java (Hibernate) version has had for some time and is now fully ported to NHibernate.
For a complete list of new features: link