As amazing as a GagaDonna collab would be for us fans, I really don't think it would be successful, iconic, or whatever else you want to call it. For some reason high-profile collabs between superstars don't seem to hold that much weight anymore. The last uber-successful high-profile collab was literally 'Telephone'.
If anything, Gaga collaborating with a newcomer (*looks at Allie X*) would probably be better.
