When I got my mini in May, at first power up it wanted to update the fw/sw on the drone and controller.  But I have never been prompted since, so every now and then I will manually check.  Still Nothing since may.  

So how often does DJI post updates?  Specifically for the Mini.  Are we due for a new FW/Sw release?  

So how often does DJI post updates?  Specifically for the Mini.  Are we due for a new FW/Sw release?  
Whenever they have something that is important enough to put out there.
There is no schedule.
They might not have anything for 6 months or even more.

No one knows. We get them when we get them.

Hello there Paulaleroux. Thank nyuo for reaching out and for the inquiry. We do not have any information when will be the exact date when a software update will be give out. For the latest DJI updates please stay tuned to our DJI official website at www.dji.com. Thank you for your valued support and fly safe always.

No schedule but in the products forum they will make a sticky thread at the top when it comes out.

Yes, just like DAFlys said, you will be notified, the app will notify you as well.