"Verisign delayed the release of their openID provider to make it compatible with Drupal OpenID." - James Walker, Drupalcon Boston 2008.
These words, casually uttered by the presenter James Walker from Lullabot, pinpoints the essential point of the session. Drupal is at the forefront of identity management in the Industry and others in the industry are looking up to it. The "others" include not only the competing CMS systems, but one of the most respected names in the industry - Verisign.
You've probably already heard that OpenID support is in the core of Drupal6, now (for Drupal5, you can download a separate module from Contrib). Right now Drupal implements Relaying Party Support only partially partially (meaning, you can use your OpenIDs with a Drupal installation). Partial implementation means that it is missing full Simple Registration Protocol (SREG) support, only e-mail and username fields are supported, and Attribute eXchange (AX) support is not available, yet. Both of these features, as well as OpenID Provider support is scheduled for the next releases of Drupal.
One very exciting feature that is already in, is multiple identity management support. You can assign several OpenIDs to an account. An example of great usage of this feature that James gave was sharing userid=1 account among developers. Instead of giving all of them the same password, you can just assign all of their OpenIDs to the account - much cleaner, safer solution.
You can find out more about OpenID in Drupal at: http://groups.drupal.org/openid