As stated above we will not be rolling to the new release due to the stated reasons.
You can still prepare for the new install though, first back up everything of value on your hard drive - just in case - how you do this is up to you whether you use an online service (like dropbox) or back up to DVD or external hard drive.
Then you know if anything goes wrong your data is safe.
During the install process you are offered the choice of which partitions to reformat, make sure your /home partition is unchecked. then when you set up a user ensure that you use the same details (realname, login, user id etc) as on your current install, that way it will use the existing /home information - should afford minimal reconfiguration (if any) for each user.
It may or may not be possible to use the 'synaptic markings' system - this is due to potential nomenclature issues and whether an application will still exist after the reinstall sio we will have to await the beta to see if this is possible or not.