No, we do not have Plus Edition in QuarkXPress 10. QuarkXPress 10 will take up the OS language for UI. So, in case you need to change the Program language, you will have to quit QuarkXPress, change the machine language and then restart the QuarkXPress. QuarkXPress 10 will automatically take up the machine language.
Plus Edition has the functionality to work with Chinese and Japanese language also, but now every single edition of QuarkXPress support all languages.