According to Robert Sitler these are things the Mayans themselves have said about 2012:

"Tzuhtz-(a)h-oom u(y)-uxlahuun pik (ta) Chan Ahaw, ux(-te') Uniiw. Uht-oom ? Y-em(al) (?) Bolon Yookte' K'uh ta (?). " "The thirteenth pik will be finished (on) Four Ahaw, the third of K'ank'in. ? will occur. (It will be) the descent(?) of the Nine Foot Tree God to (?)."

"4 Ahaw k'atun is the eleventh k'atun according to the count. Chichen Itza is the seating of the k'atun. The settlement of the Itzas comes. The quetzal comes, the green bird comes. He of the yellow tree comes. Blood-vomit comes. K'uk'ulkan shall come...." Book of Chilam Balam of Chumayel.

Source: Robert Sitler