I have also read that real (from fresh) wasabi is considerably less sharp and much more savory than the usual stuff that you find here.
A couple of years ago I was eating out with a friend, who is not fond of spicy foods. We ordered a California roll plate to share. when it arrived I saw various garnishes but not wasabi. I commented on that to my friend, who had never heard of it. I started to try to describe it when I suddenly realized that my friend was turning red and looking a little ill. I asked him what the matter was and he pointed at what he had eaten. I peered over to his side of the plate and said, "Oh, THERE’S the wasabi!" He practically knocked over the waiter running to the restroom to rinse his mouth and I did my best contain my laughter before he returned.
I’ll have to check out the freshwasabi web site.