It's very useful to me to see what people are interested in hearing about - thanks for starting this.
So does that mean you have forgotten or lost the requests in previous video threads / comments? I recall you requesting for what users are interested in and several responded. Perhaps you should consider them before accepting new requests ? You really should go through the comments of the videos, there are some good requests there.
On advanced stl topics: Not sure how advanced it would be but i'm curious of how you would implement a natural string sort function.
I've seen many versions and i'm curious of how somebody like you with good knowledge-base of the STL and how to use it correctly would implement such a function.