I dont think theyll release them, but thats just a guess. They certainly wont review the items you missed or anything like that.
If you have $100-$150 (not sure of the current price), Transcender makes practice tests that are very close to the MS exams, sometimes a bit harder. They usually come with three practice exams. If you can pass all 3 then you should have no problem passing the real exam.
If you do go with Transcender, I suggest the following:
1. Take the first exam cold - dont study. See how close you are, look at the results and concentrate on any area you did bad in.
2. Retake the first exam and make sure you pass with a reasonably high score.
3. Take the second exam as in step 1 and 2.
If you do the above, by the time you take Exam 3 youd better be passing it on the first try. If you dont, it might be a sign that you need some more real world experience (what the exams are *supposed* to measure).
The Transcender used to put references into the MS documentation as well. So for each question/answer, they give a full description of why the right answer is right and the wrong answers wrong and references to look at. Its a GREAT way to quickly learn a lot about .NET, even if you dont want to take the exam. But you have to be willing to read a lot as you go through the tests.
-Ner