Master dDo for Photoshop with this complete overview by Wiktor Ohman.
Cyborg Design - Concept Art Production Techniques
Instructor Michael Pedro gives a detailed overview on concept art production techniques in ZBrush and Photoshop.
Nondestructive Image Flattening and Reflection Removal
James Busby demonstrates nondestructive image flattening and reflection removal in Photoshop.
Photoshop Sneak Peek - Image Deblurring
A sneak preview to an incredible upcoming tool for Photoshop, that allows deblurring of images.