I don't get his examples. He talks about designs being both "usable and pleasurable", but I don't see any real difference in the designs. They both have fairly flexible layouts, attractive backgrounds and well formatted text. The only element that WuFoo has that BaseCamp does not is a "warm" color scheme.

The rest of it basically boils down to "give your users feedback, but do it in a 'fun' way." I mean, that's a good lesson to have, but its nothing earth shattering.