And Ms Wizards too! Here's a shot of the gel blob. It's white because I lime sulfured at the first sign of leaf stress.
spaz

spaz:

The first thing that comes to mind is peach twig borer. The larvae eat into the new growing tips and tunnel down a couple inches. This causes the tip to wilt. It occurs on both peach and nectarine. You will find a tunnel and possibly the larvae.

There are other possibilities since I'm not sure what I'm seeing in your picture. Could be brown rot and several other things.