They are turning all their existing accounts into OpenID-accessible accounts. If you have one you can use the URL:
There's currently no delegate option, so you can't use your own blog/webpage as the identifier but they have said this is coming soon.
Whatever happens, this is definitely a calling sign for blog owners to start implementing OpenID authentication for their users. I know I am.
Don't just sit there like a lemon! Reply!
Got something to say? Now's the time to share it with the author and everybody else that reads this posting! Lemons need not apply.