Inspite of the fact that I now appreciate John Carmack's efforts; burning the midnight-oil,
so-to-speak, I think the X-Prize is Burt Rutan's for the taking.
Ironically, he may get a late challenge by a....Canadian competitor...from the Da Vinci Project.
However, Mr. Rutan's suborbital manned spacecraft has more advantages.

The Da Vinci Project effort involves a balloon-lifted manned rocket.

(1) Balloons have a bad habit of ripping.
(2) The winds over Saskatchewan have a bad habit of being capricious during summer.
And the Da Vinci rocket could either (3) fail to ignite, (4) explode, (5) or flame out prematurely.
Five perils or potential setbacks...But good luck to all the X-Prize participants.

Jacob Samorodin

"We choose to go to the moon, and do those OTHER THINGS, not because they are easy,
but because they are hard."
John F. Kennedy