That is a very interesting and welcoming effort by Google.
A similar map for deforestation? I believe it's not so easy to do. This is because of the very varied (and oftentimes loose) connotations being attached to the word "deforestation". Timber harvesting, when done is a controlled manner (i.e. very selectively using "reduced impact logging (RIL) approach) and observes all the recommended mitigation measures, certainly does not fall under the "deforestation" category. Forests managed professionally in this way are indeed being preserved and in many cases able to halt the advance of land conversion to other uses. People always resort to clearing the forest when they thought that the natural forest by itself is less valuable economically if compared to other non-forest uses. But once you could prove that professional management of the forest which meets the economic, social and environmental expectations of the community could be achieved, then the pressure to deforest wouldn't be so strong. The case in point is the tropical rain forest (TRF).
These forests are simply amazing. The non-timber values there are a thousand times greater than the timber. All that is needed is greater investment into research and biotechnlogy development which capitalise on the medicinal and aromatic plants (MAPs) and higher awareness by those countries concerned on the value of their forests. Pressures from wood product users in the developed economies are also working well at present. These consumers demand that timber products must be certifified as having originated from responsibly and sustainably managed forest. I think this is simply great.