In the first six months of 2012, the Identity Theft Resource Center (ITRC) recorded 213 data breaches with 63% of them having no reported attributes (number of breached records, date, method of breach, etc). Compared to past incidents, this is a doubling in the number of breaches with no reported attributes. We have no idea of the scale of many of these breaches.
As the ITRC notes, data breach notification details help the public "understand trends in breach exploits and the probable consequences of a particular breach." Consumers need information in order to make informed decisions about companies they already deal with or may deal with in the future. The sharing of knowledge also helps other companies learn from mistakes of others and helps the security industry provide better solutions.
From the data that has been shared, it appears that the healthcare industry is set to reach an all-time high in number of breaches and that breaches involving third parties have doubled over last year - none of this is surprising given the trends of previous years. If you want to look at the findings from the breaches known attributes, read here.