Luckily, it appears that a public roll out isn't far away as they have now opened up an extensions gallery for developers to upload their creations. This gallery isn't yet offering any downloads, but Google says that they will open it to a small group of "trusted testers" in the next few days.
The feature will make its official public debut in an upcoming Chrome 4 beta release. In the meantime, those developers who want to slot their add-ons into Chrome can find all the appropriate information here and the option to submit their code for review and approval at the developer dashboard.
The move should help Google attract more developers and end users at a time the company is working hard to extend the browser beyond its current ~3.5 percent market share. It would certainly make life easier for users coming from other browsers -- primarily Firefox -- which may support extensions "they can't live without."