"Do I have an OpenID?" link
I'd like to see a "Do I have an OpenID" link or tool as a prominent option on the landing page. While your second main option for "everyone" tells me I might have an OpenID and not know it, when I click that link it tells me how to USE my OpenID, but not how to find out if I have one. If there is a link like this somewhere, it wasn't prominent/obvious enough for me to find easily.
I made a mockup that did exactly this:
Unfortunately, we have not been able to muster the resources to execute this idea.