There was something about this on the Science Channel a while back, as I recall Betelgeuse poses no threat to us, but if it goes Supernova in our lifetime (or more appropriately if the light from the supernova reaches us during our lifetime), we will be in for one heck of a light show, it is projected to be brighter than a full moon and gradually get dimmer over the course of about six months. But for several weeks at its peak, there will be virtually no night with the sky not getting darker than early twilight.
Additionally, there were some FR topics about the possibility. Thanks apillar.