you need some special care for this crack. Since its there, now it must be considered as an expansion joint. It will move slightly each way, so you need to allow for that.
There is a special application for covering this. You need to seek out the compound to trowel into the crack and the heavy membrane that you spread over the crack. The compound will move too and the membrane will allow movement. In this years Family Handyman Mag, it shows how to do this and allow for the movement you will have there. This crack is like the San Andreas Fault Line. Both sides of the crack will move differently.
I would recommend you doing the crack treatment but going with carpeting or out door indoor carpeting.