I remember reading a book about the life of Musashi, and it was remarkable in that he fought some of his duels against other samurai with a wooden training sword. He managed to kill several opponents armed with real Katana's with a wooden sword.
I think alot of people would tend to underestimate a wooden weapon. But that seasoned looking chap in the photo looks like he may very well know what he's doing with it. He reminds me of some of the guys down at the V.A. hospital in D.C. Some of them are from the lower economic status of Washington D.C.'s African-American comunity, and have to live in less than safe nieghborhoods. Instead of the typical old fogy cane, I see alot of homemade walking sticks that are "heavy duty" to say the least. Many look like they were part of a stout oak limb, and the probably were. Some are carved with very nice whittling, African type of designs, but its still a thinly disguised weapon for the mean streets.
These days, with ever stricter laws, I think wooden weapons will be with us for a very long time to come. Heck, they worked well for the native Americans, Celts, and Egyptions. Thats a pretty good track record.