There is a lot going on in the registry, and to enable you to stay updated, there are a variety of RSS feeds on offer. These can be used with sites such as Google Reader, or one of the many RSS clients (check the wikipedia page on for more links). In the past, there was also e-mail notification, but it confused many people, and got the registry listed as a spam site, so we turned it off.
To give you an overview, here are the main ways of using RSS to stay updated:
In addition, if you want to follow comments for just one particular plugin or forum post, there is an individual RSS feed for each of them. Look for the RSS icon after each post (), and click on it to subscribe.