I'm just starting to look at updating xlw with a view to releasing a version 6 sometime.
One thing that has made me put off upgrading the project is the pain of maintaining xlwDotNet. Given the continued active development of Govert's excellent Excel-DNA there doesn't seem to be much of a case for keeping it alive. I will be happy to carry on if there are users who require it to continue. So if you wish to see xlwDotNet in the next version then please could you give us some details on what you're doing including which compiler versions you want supported.