I'm going to ask/answer a question on a new site, guys! Let's just fill out this last form here.
Well, I don't have an account, so to register I just fill in my name and email, right?
Wrong. Kind of. It's very easy to assume the right form is for registration, rather than posting via a throwaway unregistered account. Making the fact that it's a throw away account here is a bit too complicated. Instead, why don't we draw more attention to that log in link?
I avoided the word 'or' here because it's already used in the divider
Technically you can sign up from that log in page too; and that makes a registered account, not a sad, what-if-my-cookie-is-deleted, unregistered account. By making it explicit you can register for realsies via that link too, hopefully we could get a few more registered users and a few less users confused as to why they keep losing their dang accounts. This also leaves the unregistered option totally intact.
Unregistered accounts are sort of a confusing pain in the butt; worse, with 87 sites, a registered account lets you access them all with one account. But if you're unregistered you don't get that access, and you probably don't know it. Anything we can do to goad a few more people into registering as early as possible is a net gain for the user's experience and the site/network as a whole.