I would say it depends a lot on the purpose and content of the newsletter. If it is just a "Rah rah rah!" newsletter, or a chastisement to do better, it is definitely a waste of time. However, if the purpose is for communication and recognition, then it can be very good.
My company is very global, and the quality organization is structured around quality specialties (e.g., supplier quality, new product quality, post-release quality, operations quality, etc.), so the newsletter helps the various groups understand what is happening in other specialties, regions, etc. It is also used to recognize new people, promotions, thanks for going above and beyond to help, etc. It also announces upcoming changes or events. The feedback has been very good on it.