Mig, Nath,
Thank you so much for your kind words!
Beside the description of the steps I took to get this result, I'm attaching a snapshot of all the Layers involved.
Mig, I usually start by examining the Channels and working on, or sometimes replacing, the worst one, but in this picture they were all very bad and trying to keep some of the original colour, I decided to try a 'global' correction
What I did is the following:
1) Used the Curves (snapshot attached on my next post) to lift the shadows and bring out the lights.
2) Hue/Saturation Adjustment Layers to further correct the colour.
After this, as you can see from the attachment, it was Layer upon Layer (Blending set to: Overlay, Soft Light, Color Dodge) to separately correct different parts of the picture.
To 'clear' his face from .jpg artefacts I created an empty layer and used the Blur Tool (fuzzy brush set to Color, Opacity 80%) after which I used the Healing Brush (sampling from a 'Pattern' I created for this, Tip from Katrin Eismann's new book - if you don't have it yet, I'll send you a description

) to further remove splotches and shadows.
Finally, to slightly sharpen the picture, I used the USM
Amount: 30 Radius: 20 Treshold: 4
P.S. I always 'play' with the Opacity of the Layers I add ...