over heating

today when i was driving on the highway going about 80mph, not hammering on it at all, i noticed the temp gauge was all the way up towards the hot, so i pulled over turned it off and popped the hood and there was oil spraying from what looked like a hose underneath the ignition box where the plug wires plug into, does anyone have any idea about what could be wrong and how much this costs and if it could create future problems... luckily its still under warrenty!!

by the way its a 97 lude si auto