It says "Currently, 802 guests and 43 members are online." .. are all dormant here ?
The question you are asking is way too broad, how far have you got learning Nukes to see what it can do for you?
Also have you considered Portal? The first release candidate is now out so it is moving towards the production release.
Following your lead i had a look at portal. I managed to get it up and running but I can see only forums in it. I need more features like
-Photo Album (i guess i can ue CMS for this)
How do I get these in JBoss Portal ?