Just wanted to let everyone know that yesterday I released an early version of JsonCF - a JSON serializer and deserializer that targets the Compact Framework (v2.0). It can also be used to target the normal .NET framework (binaries are included, as well as VS project). Use it at your own risk - it's very early in in development and poorly tested. It's up on CodePlex at http://www.codeplex.com/jsoncf/
I don't think it's absolutely necessary, but I do think .NET developers should be familiar with basic aspects of Reflection and the Type class. It isn't important to know every class and how every method behaves, but rather what's possible and what isn't. Writing a serializer (my second one now) always provides good insight into .NET reflection.