This article on CNN sums up just about every point ever made in any biometric article.

1) The technology in large part still requires adaptation, and it’s important to remember you felt that same trepidation when PCs, ATMs, credit cards, and online payments first appeared. 2) It’s becoming evident however, that biometrics could bring more to the table considering it is practical in so many environments. 2) Biometrics have usually been implemented for convenience or for security, but in the last 3 years decision makers have seen them as being dual purpose. 3) The technology isn’t the answer to everything. When bundled with another security tool such as passwords, RFID, or another biometric (multi-modal biometrics), it provides the final layer that could really create an ultimate security tool. 4) A biometric is not replaceable. So how much of a concern is it that it might be compromised? 5) There is much more work that needs to be done in order to regulate the usage, increase their effectiveness, and be successful in some large scale deployments. (However the US and UK tend to disagree with this, by announcing their plans to move forward with projects relying heavily on the technology.)

Biometrics must balance privacy and security.