How do I add a new entry to the "New Solution" panel in Xamarin Studio in an addin?
In your project.addin.xml you have to add /MonoDevelop/Ide/ProjectTemplates extension path entries. And then also add new project template file to your AddIn project resources(simply add file to your project and mark it as EmbededResource). Make sure resource names in project and /MonoDevelop/Ide/ProjectTemplates match.