Xenogear sold about average numbers in Japan, not that big. Xenosaga sold's leagues better than Xenogear because people were interested in "OMG HOT ANDROID KOS-MOS" and the pedophiliac sex object "MOMO" before even got into the story and appreciated it, before they finally spread the word into others . So yeah, first they're basically pedos.
NOT YOU OF COURSE.
So let's talk about the story shall we?
Spoiler:
I think the anime will start with the explanation about the Kenyan incident, with the Japanese profesor and the Kenyans about discovering the Zohars, continued by a long explanation blah blah blah, and then in the middle, Shion will be introduced, blah blah blah, ending it with the awakening of Kos-Mos.
Oh and yeah, maybe this series are bound to have Momo's panties all over again. Good God.
And holy crap, I can't believe I forgot about Gungrave. Best game -> anime adaptation ever.