Some sections of the forums are less active than others. For example, the Hobbies forum is far less active than the General one. So the activity depends on which section you're in. I tend to mostly go on the General forum and the debate ones, like the Politics and World ones. The forums aren't as active as they used to be but they're pretty active still. I go on the forums from time to time, though most of my time is still spent around the blogs.
So the short answer is yes, the forums are still used.
1. Yes, I use forums. 2. WWE and baseball forums, no. But I do post in others. A lot of people use forums. The more popular ones are under general and contests. There are others, but those are the only two I ever notice to be used a lot.