SDKBOX is more like a upgraded version of plugin-x, so in short it's just a plugin it's not something runs on a cloud. the reason it starts is because we want to provide a better plugin integration solution for cocos2d-x, but the fact is plugin-x always gets the low priority compare to other shinning new 3D features, so we decide to change that.
Now we're working with third party sdk providers to create fully tested plugin for cocos2d-x c++, js and lua, and we got sponsorship if developers integrates them, as a result currently we're tracking installs of our plugin (only install nothing else), and that's pretty much the services we got at this stage.
Moving forward, we're creating more plugins, like iap, social, and will provide more useful valuable service. to the developers.
It's really a win-win for developers, 3rd party sdk providers and coocs2d-x, saves game developer's time, saves sdk developer's time, and we get paid to grow cocos2d-x.
As for AnySDK and SDKBOX, currently it's a separate product, SDKBOX offers more freedom and more tailor to US/EU market, although AnySDK have english version, but I think chinese market really keeps the team busy, 100s of store to keep it up, is not a easy task.