The most prominent project I've found is this CodeProject article, dated 2002!
With this project, we'll be updating NETMaster's original code (written for .NET 1) to the newer versions. We'll also improve the calls of the wrapper so it's much more developer friendly. Ideally we would have a single .dll file and have him call methods like:
Image myImage = SharpTwain.GetImageFromScanner();
See how easy it would be to use it?
A LOT of the legwork has already been written by NETMaster, basically we'd be changing the way the project is structured and also using newer constructs that weren't available back in 2002.
I'm looking for people that are interested in the project and would like to contribute. This will be 100% open source and hopefully will become THE library to use when wanting to interface with a scanner.