Re: Who understands deviantart?
Seeing how big (in users and content) deviantArt is and how “easy” it is to use, I would give up on making such a website. Even if you come with a better concept or a better UI, they’ll notice you and build their own even better. It’s a war you cannot win. Just like it’s impossible for Bing to ever beat Google.
What you could do is make such a site for a specific user group or specific country and see how that works, here (netherlands) we still have a social network that is used more then facebook and those users wont jump over to facebook anytime soon either. That network (hyves) is only based on the Dutch people and is most likely therefore still more populair.
If your website start growing and users show interest, then you can think about building your site bigger and better then the big bad competitors.
Like all populair sites, start small and see where it goes.