Does Myers-Briggs Type Indicator tell something objective and predictive about the persons decision making tendencies? In other words, can a Myers-Briggs score give you useful information about what decisions a person is likely to make in future scenarios, or about his/her abilities?
Actually, there is little evidence to support that the Myers-Briggs gives us much useful information, at all. The M-B was based on Jungian ideas, but the people who developed it were not even psychologists. They based the questions on a variety of things, only some of which can be linked to Jungian ideas on psychology. Jungian ideas have not necessarily been supported, consistently, when tested. The test, itself, has shown to be problematic in determining behavior simply because people's results are often inconsistent.
Basically, the MB test is a very widely used measuring tool which hasn't been proven to be either consistent or even very useful.
There's a decent breakdown of the history of the test and its flaws at skepdic, here.
I was able to find this study which seems to indicate that the MBTI was predictive for the Extravert/Intravert and Sensing/Intuition dimensions. People who ranked high on these tended to be in jobs which aligned with their scores.
I could not find any studies which focused on the abilities of the person versus the MBTI score, so I'm not sure a correlation would make sense as the test focuses on personality and not skill.