Upgrading will give you the new default applications but will not remove the old defaults because many people may not want the old applications to go away. For instance, Gimp used to be in the default install. Those that don't want the old applications are free to remove them manually.
The exception to this is if new tools conflict with previous tools, then the previous tools will be removed, but this shouldn't be the case with apps like music players or photo editors.
LibreOffice as far as I can see is replacing OpenOffice.org. The version of OpenOffice.org that Ubuntu and most other Linux distributions were shipping had several patches from Novell that Sun/Oracle never accepted but are now included in LibreOffice. I don't even think there will be a 3.3 build of OpenOffice.org in the Ubuntu repositories and trying to keep both installed isn't really useful.