Analysis: False. NASA has predicted no such thing. Indeed, the phrases used above — "total blackout of planet," "alignment of the universe," "shift from the current third dimension to zero dimension," etc. — are not only undefined, but meaningless. It's pseudo-scientific nonsense.
The "alignment" to which our unknown authors refer is probably the passing of the sun, as seen from earth, across the approximate center of our galaxy on Dec. 21, 2012 (the winter solstice in the northern hemisphere). This happens every year at about the same time and portends nothing in terms of earthly events — good or ill — given that the galactic center is some 28,000 light years (165,000 trillion miles) away. It's a cosmic non-event.
It so happens there's a super-massive black hole at the center of the galaxy, and, as everyone knows, black holes are mysterious and scary, so purveyors of 2012 doomsday scenarios have used this as an excuse to speculate that the aforementioned "alignment" may in fact wreak physical havoc here on earth, somehow. But again, we're talking about a cosmic entity unimaginably far away from our planet and a celestial alignment that occurs every year like clockwork, and has throughout all human existence.
What's so special about 2012?
Answer: nothing.
About the NASA video: Most versions of the text include a link to a two-and-a-half-minute YouTube video showing NASA Administrator Charles F. Bolden, Jr. recommending to employees and contractors of the space agency that they develop family preparedness plans in case of unforeseen emergencies. It was recorded in June 2011. Its message is routine, generic, and has nothing whatsoever to do with "dimensional shifts," "alignments of the universe," or a "total blackout of the planet." View the video in its original context here.