I think of the idea as rather humbling, not vain.
To think that God created man in his likeness is vain.
I'll give the IDists this at least, they haven't explicitly claimed that man is the end all and be all of the 'Intelligent Designer's' efforts. I guess they're open to the idea that we are a failed experiment that will be left to self destruct. This is as plausible as the other implications of their 'theory'.
I find it rather humbling to think there is something beyond ourselves, and that that "something" is not random chance.
Of course, we all know those who believe in evolution aren't vain. ;-)