I've been compiling a very long list of available domains, much of which are short and keyword(s) in domain + "talk" or "forum(s)" or "discuss" immediately afterword.

My thinking here, is I would like to start up another website (or two) that is entirely community/forum based, and my questions are:

Is it worth it? Essentially, after initial start up and forum begins to get large, as the admin I can begin to appear less and less. Moderators and global moderators will handle most of the work associated with forums (deleting spam, banning members, etc).

Are forums still as popular today, than say, 5, 6, 7 years ago before social networking grew to the size it is today? What sort of community based websites do well?

Marketing. How does one market a forum, when viable alternatives exist? Why does one do well, and others, not so well? Many forums on the web discuss web design, internet marketing, and things of that nature. Why is webmaster-talk a larger one? (EDIT: Saw the stickied forum marketing thread. Please don't move/merge this thread, you can delete this paragraph though)

There are atleast two top-level (although not listed as top level/premium domains) domains available that cater directly to two forums or community based websites I would like to start up, and I am doing some research before hand. I ran one before, used to have 1,000's of members, but this was back in 02-03 when I was just a kid. The game has changed now, I would guess and I am seeking some input as I consider these options.

Forums and online communities can be very successful if done correctly. You need a site about a topic that lots of people want to talk about and you need to market it well.

I would also suggest a highly moderated site. ChrisHirst and others here delete LOTS of crappy, spammy posts. If you allow such "crap" to remain on you forum/community the users who are actually trying to contribute useful info and participate in useful discussions will leave.

If your forum covers a popular subject that attracts a lot passionate people, then there's a good chance it will become popular.

But it sort of sounds like you're trying to back away from it before you have even started, so maybe you need to examine your true motives/feeling before starting down that road.