Phil Moyer of Hyperon agrees with Wood in regard to encrypting transactions. He also concurs on the usefulness of digital certificates. I'm amazed that so few companies use digital certificates. They solve a spectrum of EC security problems, and are well worth the investment of building the infrastructure. Specifically, digital certificates can solve or significantly mitigate the problems of user-selected passwords.
Users consistently choose weak passwords.
Users consistently use the same password on site after site. Customer support organizations must have a way to change user passwords. Digital certificates can help resolve many of these issues. Repudiation is another problem. It could be a huge problem.