Fedora is not a continuous system and sometimes the changes made can span more than two versions.
preupgrade is for an intermediate user that has bene following Fedorda N+1.
It requires knowing about the changes and bugs of the release or pre-release repo.
But by waiting, any user can download the DVD and install it.
To upgrade N+1 boot up the DVD and it will see your old system and show that it wants to upgrade.
By doing this the system will obsole old packages, and make strucure changes better because the f/s is being treated like data, not a running system.
In the case of F16 to 17 I would use the DVD for best results, but some knowledge of the boot and recovery process is required, otherwise a clean install will be the only option.
For best results, stop updating the FN and wait for the DVD and a couple of mounts of updates (these udate repos can be used in the install (don't know about an upgrade), but even so, the first yum update after the first boot will clean up a lot of bugs.
If you are a current events type install rawhide and liva la local.