The recent debate on teaching of "intelligent design" (for example, here) is premised on the offering of ID as an alternative to, and contradicting, Darwinism. If your version of intelligent design also included the idea that Earth was created about 6100 years ago, then this contradiction is very much alive. [This version of fundamentalism should not be too hard to combat in the educational system, since it also contradicts grade-school-level knowledge in geography, history and astronomy.]
For those less fundamentalist, only one premise is needed to unite the two views:
God is smarter than you are.
Armed with this axiom, we need not suppose that God directly designed the phenotypes of today's creatures. This attributes to God the intelligence of Man, which is a common enough error but, to my mind, more offensive than determined atheism. Instead, He would only have to choose the parameters of His universe so that they would, in the fulness of time and acting according to their own natures, bring forth the creatures he desired, having the requisite attributes to be imbued with souls.
This idea has appeared in literature, most notably in Stanislaw Lem's A Perfect Vacuum, most explicitly in Iain Banks's (otherwise otiose) Excession.