Got the official release installed and had to make a couple of changes to my nullable code that was written against Beta 2. All good, though. It was just taking out hacky crap that branched on INullableType in generics code. Glad to see that nullable types are null when boxed now. Way to go CLR team!
However, the ADO.NET stuff isn’t quite there yet. But at this point it’s not so much a nullable type thing instead a matter that DBNull just isn’t null, so you can’t just cast a return value to a .NET type. Still makes writing typed DB interfaces a bit annoying. But with generics, it’s at least worlds better than it was before.