I saw the article on CodeProject as well and downloaded your source.  Looks like a nice job.

I'm particularly interested in the BIP32 support. So once I get a chance to dig in a little deeper I think there's going to be a lot to explore.

I'm not sure if you've seen it already, but there's also another C# project that is in progress here: https://github.com/pmlyon/BitSharp.  It aims to be a "fully validating Bitcoin node".

The developer there is good... may want to peek it for ideas or find some basis for collaboration.

Great work!