Whenever I see something like that, I am certainly impressed by it's performance but I ultimately always end up being more amazed by the thought and engineering that went into actually producing the equipment.
Wow! As impressive as that is, it is too bad the forests just won't grow as quickly. Sometimes I wonder if our "efficiency" will be the death of us all.
I agree with Warren, as a retired draftsman i guarantee that there were many hours put into this machine, but then machinery has always amased me at all the working parts and the number of people that come together to make all these parts work, killer video!
That's actually been around for quite a few years now. Check out the History Channels' Modern Marvels. One of my favorite shows. It's used mostly for sustainable wood for the paper industry as you can see by the size (diameter) of the trees they are harvesting. So don't worry to much that it's going to "clear cut" the continent.