I opened the image in ACR, adjusted contrast and exposure and fixed red/cyan ca as best I could.
Opened into Photoshop. Added a brightness/contrast adjustment layer for the sky and masked the foreground.
Added a small edge vignette,
Enlarged the background layer and filled with light tan for a "canvas"
Simplified the image with Buzz Pro Simplifier One.
Smudged the edges of the image layer
Added canvas texture to a Soft Light 50% gray layer.

forum discussion: http://forums.dpreview.com/forums/read.asp?forum=1006&message=34198246
original image by Macdeb: