In a few weeks Apple will launch the official Safari extensions gallery, so you’d better hurry and go submit yours now. But in the meantime, unofficial Safari extensions websites have flourished all over on the internet.
The current state of Safari extensions? There are a few great ones, lots of cool ideas, hundreds of stupid and buggy userscripts ported to Safari. Last night the Panic team offered an exclusive Twitter preview of their upcoming Safari extension, Coda Notes, which they previewed at the WWDC in June.