An ancient civilization did not have some greater insight into how the galaxy worked. If people really believe this kind of shit, they should slap on the ole tinfoil hat and dig a hole big enough for them to hide in until 2013 arrives. The mayans and whatever primitive ass stargazing tools they had did not tell them more then our modern day satellites and probes are telling us.
depends how you look at it, maybe the the Mayans where not predicting the future but instead only charting there own star path, but the path they charted when creation there calender is a cycle which is on a repeat course to which we are now approaching the end of that cycle.
We will now come december next year if in fact Nibru does exist or not, which marks the end of the calender, it should be visible to us by then, what effect been so close to the tenth planet or planet X will have on the earth is anybodys guess but ether way come the end of next year we will know for sure.