Amin, this is quite amazing, as just recently I was wishing you owned a Nikon forum. In addition to m43, I also shoot Nikon, but haven't found a Nikon specific forum that I enjoy and frequent nearly as much as the forums you run.
I'm very excited about you taking ownership of the Nikon Cafe site, as I also belong to Nikon Cafe. For me, it's the best of the Nikon sites, with an environment similar to the sites you run, but still falls short in several areas. Hopefully, you will incorporate changes that bring it more in line with the rest of the "family".
First, and foremost, I would recommend adding the "like" and other buttons. It's a quick and effective way to acknowledge, or comment on a posted photo. This change alone will make me a much more active member, as I won't have to take the time to write out a comment each and every time. The way it stands now, I usually just don't bother commenting at all.
Good luck with the new site, Amin! Your involvement cannot help but make it a better place for Nikon shooters to frequent.