You can read about the details of the update here: http://fedoranews.org/blog/
It is hard to classify the updates; they run the gamut of "os updates", programs, system utils, etc.
However, Yum update will not result in any "newly installed programs." Yum knows what is already installed, and "yum update" only updates what is already installed. If a package is updated, but you don't have it installed, yum doesn't install it. You would use "yum install" to install new packages you might want. And yes, they do sometimes automatically go into a menu group, if they are designed that way.