So this article came out last month and talks a bit about what Sitchin believes and what he's trying to do, almost as a final act if you will.
Basically, the London Natural History Museum has the 4,500 year old remains of a high ranking Sumerian woman. Sitchin wishes to compare her DNA to that of modern humans to see if there's anything odd, different… alien, if you will.
He says, simply, that he's risking his life's work on the outcome. Mike Heiser of 'Sitchin is Wrong' in return says that if a test were to take place, anything unusual could be jumped upon in order to claim a victory of alien DNA, and of course there's no alien DNA from elsewhere with which to compare it.
However, the Natural History Museum will only listen to requests that form part of a recognized research project, and preferably with experts in the field, rather than a book writer with a passion for pseudo-history.
And above all, he wishes to not be linked with 2012. He did after all only set out to propose that alien gods genetically modified humans in order to mine gold, and that a retrograde planet swings through the solar system every 3,600 years, based solely on trying to apply select elements of the Babylonian Creation Myth to the physical creation of the solar system.
So, you know, he doesn't want a collision or anything in 2012, no. That'd be nonsense…