Vanity URLs are a strange thing to have, at least if you have so many of them. You have one on Twitter, on MySpace, on YouTube etc. and soon also on Facebook, starting on saturday. They are going to be so popular, Facebook even created a countdown for them. Now of course it’s silly to create one over and over again on those networks which happen to be popular at the time being. This is especially silly in case you already own your own domain and e.g. run your blog on it.
Nevertheless the importance of these things shows how people think about these URL. They are important to them, they are as important as not even more important than email addresses (depending on the generation you are asking).
Now what does that mean for the lengthy debate (the link actually is from 2007, so you see how lengthy it is) about whether OpenID should use email addresses or URLs? I would think, that URLs will be winning in the long run. We see already how people think in terms of their vanity URL about themselves, this is their identity (or actually set of identities) on the net. It’s not the email address which usually is kept more private due to spam.
So as more and more services are moving towards such URLs and they more and more become mainstream, does that mean the OpenID URL approach and through this OpenID itself will become more popular and understandable, too? I would think so.