You have probably heard, the SL Blogs, Forum, Knowledge Base, and Answers are open for posting. The new community system integrates them, which is supposedly better than the previous system.
Torley has a spiffy looking new tutorial on the new system of Blogs, Forum, Knowledge Base, and Answers. See: Torley’s Welcome to the New Second Life Community Platform
To set your avatar picture in the new system, you’ll want to watch the new tutorial. The information is at about the 5 minute mark. Not exactly fun and easy… but not too bad.
If you use a reader (RSS Subscription), you need to create new subscriptions.
General Discussion seems to be missing in action. The new Answers section has this: Is there a place for general discussions here? – Not much help. The General Discussion (GD) section of the previous forum was a topic of many threads. Many felt it should be removed. It was sort of like having a miscellainous section in filing, which creates filing problems. Whatever the case, it appears the GD section of the forums is gone.