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This is how I see it.
You have a forum to discuss domain names. If all you want is a forum then don't bother to change however, with XOOPS you could:
1) Have a directory of domain registrars
2) Have a glossary of Terms concerning domains
3) Have RSS news feeds about the subject
4) Write a blog
5) Have a classifieds section for domain sales or an auction.
There are many more things that you can do with all the modules that exist.
You are more likely to be successful with XOOPS because the functionality persuades more people to become members and contribute.