The way the BETA exams generally work is you will be given more questions than the final exam, this is to get feedback on the various questions VMware had in mind. This can span the depth of a given topic to difficult of a given question and you will be able to provide feedback on each question, at least that's how it has been in the BETA exams for the VCP, VCAP4-DCA and VCAP4-DCD all of which I've taken part in the BETA program.
As you have noticed, there is no passmark set because it is currently unknown yet, that will be determined by VMware after the BETA exam in which they'll finalized a score and select the questions they feel best fit the content based on the feedback. Receiving your scores can take up to 2+months if not more as it has been for most of the BETA exams. If you pass the BETA exam, you pass the actual exam, it's just in the BETA you get the breadth of all questions where as the final exam, you will see a subset of those questions. The other added benefit is not only the feedback you provide VMware but also a nice discount off the regular price and hopefully you are not mandated to take any required course which can run up to $3,000 USD
Good Luck
