Hello,
If you want to reuse the same JSP page from a dialog and wizard, yes, it is possible. Simply access to your bean with the syntax #{Container.xxx} instead of #{DialogManager.bean.xxx} or #{Wizardmanager.bean.xxx}.
If you want to use the same bean for both dialog a and wizard, you'll have to create 2 classes, one inheriting from the other to put all common methods in the parent. Have a look at Alfresco beans : CreateSpaceDialog/CreateSpaceWizard from instance.