They'll never be as good as they were, but it's worth trying to fix them.
http://www.ehow.com/how_8678291_fix-delaminating-skis.html
Remember that epoxy is carcinogenic. It's non-volatile so you can use it indoors, but make sure you don't spill it on anything and wear gloves at all times. After it has been cured it is safe to touch.