Instead of forming partnerships with existing sites to share information, why not start a VGChartz hub-like network, where other startups, like VGChartz form together, preferably with people that are already with VGChartz. You could oversee that it sticks with how YOU want the VGChartz image to be, they'll maintain and do everything that needs to be done to keep the new sites active, and then it'll all be accessed through one central site, which could be here, with links to corresponding hub sites. One site could be a blog just about news, like kotaku pretty much is, another can be previews, reviews, like gamespot/ign/whatever. Keep it simple, but offer what people want. Pure content with minimal ads, a simplistic, yet sharp looking site, like VGC, and that's about it.
So basically, all you're doing is assisting people with the determination to further VGChartz, have like a centralized community forum for all of them, but keep each site directly relating to what it is. Sales here, reviews there, blogging news over der!
Might take a little time to find people with the ability to update the sites with the functionality and what not, but it'd give you complete creative control and no need for reliances on other sites that have their own agendas, Just my thoughts.