I guess that first one should really read "currently, *A* major O/R mapping framework available to .NET developers is NHibernate". I did not mean to imply that NHibernate is the ONLY O/R mapper available, but that, with the amount of momentum behind the framework pushing over from the Java side of the fence that it is a major player. Regardless of how poorly I worded that sentence, the following one ("you can only get NHibernate at present") was a contrast to ObjectSpaces, not the rest of the O/R mapping world.
I don't mention the myriad other choices because I chose to demo NHibernate. In retrospect, you are right, I should have run down a list of other available choices. Good call.
Finally, you are right, there is no exception handling in my sample code. I rarely add it to code in my articles unless it pertains to a specific point I'm making, because it makes it harder to see what I'm actually demonstrating. You aren't the first to complain about this, but I think it normally makes the code clearer.
Thanks for the feedback...I'll do better next time.