Is there any way a file upload dialog like this can be implemented:
yes, can be implemented.
Title and description is something internally implemented on core but what I have still not get time to show in UI, during this month I will doing it.
About document date and creator is information directly captured by uploading and is not needed to set in file upload form. This part is still not yet done if you want to collaborate in extractor metadata document information you're wellcome.
About keywords, categories, types ... can be set now ( simply enable on profile wizard ) from version 6.0 has more complex ( http://www.openkm.com/en/openkm-smart-tasks.html -> depending folder can assign some metadata or others automatically or select which should be shown to user )