Please add my +1 to this feature too.
I set my Test Case to a status of 'In Progress' while I test each step. Once I have tested each step, it would be great to then set the overall status to Passed, rather than adding another Test Result.
This is especially true of when you have many test steps in a Test Case.
At present, I have to create another Test Result and put a note to tell people to check the previous Test Result for details of each test step. The alternative would be copy and pasting in those test step results to the new Test Result which would be a pain, particularly if you have a lot of test steps.
I really like the fact you can setup your Test Cases with test steps and to be able to edit the overall status would be the icing on the cake!