Zecharia Sitchin has done a lot of research...he has taken the time to do an extraordinary amount of reading and blending of texts from a variety of sources into a remarkable story. It is a shame that there is so much conflict and mistrust in the physical landscape/area he writes about. It would indeed be interesting to find the ruins he speaks of.
Notice I used the word story... It is not my place to say whether Sitchin is 100% "right on" in his books. It is not that the line is too far out or that it is because we have not found this extra eliptically orbiting planet... There are some creditable sources that suggest this planet 'may be' and some that even suggest that according to some calculations it 'has to be'.
There are however, some parts of his interpretation that are questionable and some that are indeed extraordinary. I have a dear friend and teacher who strongly suggests that "the real history of our planet is stranger than science fiction fantasy".... Might there be another reason besides oil for the USA being in Iraq? (I have never "bought" the democracy line, even we do not have that).
Sitchin weaves an interesting fabric with a lot of research...it is up to us to discern the truth and walk in paranoia or adventure.