I don't like the Disqus and Facebook things, or separate accounts no matter what social media service you are using.
From the little I've seen, I also am suspicious towards the forum/discussion format of Gamewise. It doesn't look appealing. I have only seen it from the surface though, I don't know how it actually looks when you are logged in.
I don't want to be negative and contribute to any failures, but I have a feeling we will see another overhaul within a year or less, and that lots of stuff will be merged together again as they were in past.
Btw, I don't seem to be able to access the page where you can add new games to your collection (here on vgchartz). My existing games are still there with their rates and all, but is it correct that the feature to add new games to your collection was removed when Gamewise launched?