Pictures often fail to capture the proper sense of a place, due to the cropping, field of view, color mapping, etc. Image editing is a delicate art, and there is no set fast set of rules to follow, but the objective should be to try to restore some of the life that was lost in the imaging process.
In some cases, switching to black and white just adds something amazingly mysterious and indescribable. If you don't see it "pop" like this, then don't do it. A good candidate for this is pictures that are over-saturated to begin with, and naturally high contrast. In this case I don't think it adds anything...but in general, low contrast black and white is never good.
This picture seems a bit unbalanced to me (not that symmetry is good), and I think part of the problem is the aspect ratio. It would look better as a panorama. Also the foreground is too dark, but I don't agree with the way Andre put the brightness through the roof and over saturated the distant mountains.
Here is how I would edit your photo:
Original
Edit
http://img197.imageshack.us/img197/2058/edito.jpg
Of course, a landscape such as this is not going to look impressive at such a small size no matter what you do to it. With a little more kung fu, we can upsize it a bit without it being too noticeable,
http://img188.imageshack.us/img188/1499/upsk.jpg
The full list of edits were to change the histogram (but only for the foreground), slightly increase saturation for the forest and city in the lowlands, then upsampled and added some high freq back into the rocks (but not the grass, to avoid aliasing).