I moved my little demo application (aka FoodBankTracker) that I use for demoing tech over to Visual Studio 2007 / .NET 3.5 today without much hassle.  The only real hassle I had was with log4net version/strong key mismatches between MonoRail RC2 and NHibernate 1.2 GA, but that's entirely another story.  The main reason I wanted to move it over to the new platform was to really try out the new language integrated queries (LINQ).  I ended up using the LINQ -> NHibernate criteria adapter being maintained by Ayende for several reasons:

1. My NHibernate mapping files are complete.
2. I like the unit of work NHibernate provides.
3. Its always good to have some abstraction between the domain and the database layer.
4. I'm familiar with NHibernate and already have infrastructure in place for it.

I grabbed the latest code from subversion for the LINQ -> NHibernate adapter and was up and running in no time.  The only change I had to make was to upgrade the NHibernate version from 1.2 beta3 to 1.2GA.  The hardest part was figuring out that I needed to add an assembly reference to System.Core for .NET 3.5 in my project.  Anyway, here's the one test I have working with LINQ and for comparison I'm also showing the original test without LINQ which does the same thing.