In my opinion there is a severe problem with the way the drupal6 OpenID module treats login procedure.

Example:

  1. Alice runs a page with activated OpenID and comments.
  2. Bob has an OpenID and wants to comment on Alice's page.
  3. When bob clicks "add a comment" he only sees two links: LOGIN or REGISTER to post comments.
  4. At this point Bob has no clue whatsoever that he could login with his OpenID and creates a new account on Alice's page.

Unless I'm missing something really essential this is broken.
Everybody needs to know right from the start that comments can be made with OpenIDs.