The forum, along with many other systems that require accounts such as IRC services, to have some single-sign-on system where people can have a single account over several services.
One major benefit is that people can write and/or integrate [glow=green,2,300]SUPER EXPERIMENTAL[/glow] applications that require remembering who someone is.
This already exists for Wetfish, however the forums were quickly put together in a weekend a year ago and Justin never integrated wetfish logins - https://login.wetfish.net/
I think it would be cool if our account system worked like Braintree hosted fields - https://developers.braintreepayments.com/guides/hosted-fields/overview/javascript/v3
If you already have a Wetfish account, registering a new account would be as simple as clicking the "login with wetfish" button, but new users would register through Wetfish Online directly. The username / password inputs would be iframes, so projects could use Wetfish Login while maintaining a seamless registration process.