Next Sparkast?

So its been a while since we recieved our last sparkast and 343i usually releases them after big events… which leads me to my main question…

When do you think our next sparkast will be and what to you think it will/should be about?

I cant remember who but david ellis or frankie said on neo gaf way back in early august that there would be a sparkcast in late august that goes in depth with the sandbox and explains alot of things. Yet we havent heard a single thing about it -_-