It would be quite nice to be able to configure the default category for new cases on a per-project basis.
This should also apply to incoming emails so that if I have a mailbox configured to always place incoming messages to a specific project I could specify the default category for those to be something other than "Inquiry". This would allow to ensure that cases going to that project follow a specific workflow. I don't see another way to configure this at the moment.
For example I created a project called "IT orders" and using the workflow-plugin created a category and corresponding workflow. However any case submitted by email to this project by default is of type Inquiry and thus will not go through the desired workflow unless someone manually goes and edits the category for each incoming case.