With wp-discourse you can only select one discourse category in which your posts get published. In our context we have multiple categories we want to use and to be able to select that per post; blog posts to Blog, and product posts to Products.
I modified wp-discourse to add the category drop down on the publish meta box, and used it as the published discourse category. I have my code on github, I think its a neat idea and I would like your feedback. Check it out:
Let me know if there are any bugs. I also added a field in the options that allows you to force update the category list (Just something I needed while I was setting up a new test discourse site). But I am not sure if its the best way to go about it, or if its needed.