More from the "I can't believe he knows this stuff department":
I once worked for a bit in a factory that actually made laminated windshields. Duplate Canada, which was located in Hawkesbury (near Ottawa) in Ontario. It was taken over some years back by PPG and still operating. It is a fascinating process: automated machines score and break the shaped glass out of blanks; vinyl is laid down on one, the other lite placed on top. Then a vacuum is applied to the edges and it is baked in an oven to bond the glass to the vinyl. It then was placed on a special frame and baked again, this time to actually melt and bend this glass/vinyl/glass sandwich to the contours of the required windshield being made...and oh BTW, the tint band is in the vinyl, not the glass.
Now, all that being said, a windshield sells for something like $500-600. So, if there was a repair method, first you'd have to get the glass out of the car, rig up some kind of repair method to get to the edge that has lost its seal, and reinstall.
My guess is it could be done (like the way they repair chips today) but with the cost of removing it and reinstalling it (and the inherent chance of breakage along the way) my guess is when it becomes bothersome, replace it.