It's confusing and difficult for novices and elderly and I can't install it on any client computers any more, because every time Firefox starts up there's something.
If it's not bragging about a new feature, it congratulates the user for upgrading to the most recent version (seriously, just keep it quiet).
Make a shiny "see whats new" button instead. If people want to know, they can click on it. Otherwise, please stop stopping me from installing this for clients.