In KDE SC 4.9, Kate Part will have an option in the Open/Save config tab called
[ ] Append newline at end of file on save
By default (and Kate tradition), this option is off. You can also use the document variable (modeline) newline-at-eof [bool], either in the file itself, in a .kateconfig file, or in the “Modes & Filetypes” config page. If a newline was added, it is visible only after reloading the document. This finally fixes wish #256134.