Well, the Shroud is either a fake; real and the image of Christ; or real and the image of someone else. The scientific evidence to date has all but ruled out fakery. The chance of it being someone other than Christ is extremely small. And if it is someone else, then yikes!
I am convinced this Shroud is Jesus' way of reminding us of his relevance and power. The fact that it's endured the test of time is proof enough for me.