Marketing departments often use these documents to write their own, hyped-up copy for advertisements or blog posts, but your own appraisal of differences should use a more neutral tone. In six months, the features described in the change log will no longer be so novel, but they will still be online. Readers shouldn't have to parse a corny sales pitch about the incredible potential of a new feature in order to learn that push notifications arrived in version 1.8.2.
