What should be included in an extended abstract (CS)
The content may include the following, some of which may overlap with the points you have mentioned already.


Definition and scope of the topic
The problem you are to focus on the topic
If the problem was faced before, describe the state of the art.
If you are introducing the problem, express the importance of it.
Discuss the methods and novel techniques to be employed
Highlights of the results obtained
Possible future enhancements and further work in progress


Some extended abstracts also allow the use of references, consult with the publisher/conference committee for any clarifications. 

The extent of explanation on the above points is confined to the constraint of the maximum length prescribed by the publisher/conference committee you wish to submit to.