Similar existing use cases:
A couple of real worlds examples are Google Play app reviews and customer reviews on Amazon. What they have done is, they have read all the comments mentioned and summarized it saying that these are the reasons why this app is good and these are the reasons why it is bad. A really good use case.
Use cases of the idea:
One use case I have figured is in the education domain where students can understand complicated topics within minutes.
How can it be built? Definitely through machine learning. Sequence-to-sequence learning model is the model that needs to be trained.
For our POC we can make a model taking the data from Two Minute Papers and see if it gives good results.
Challenges I managed to find out one big challenge till now and that is transferring the learning from one domain to the other as the Vocabulary is not shared. Meaning, a model built for the medical domain could be really tough to be used for engineering domain.