We have 2 scheduled releases per year. A release is a version for which Hippo offers paid support services. See http://www.onehippo.com/en/support for more information about paid support services. See the CMS7 roadmap for the development roadmap of Hippo CMS7.
Issues we fix for customers and community are made available through tagged artifacts. These tags are announced on the public mailing list. At the end of each month we create Hippo maintenance versions based on the intermediate tags that have become available.
See this faq for our end of life policy.