Well, this is maybe not even worth calling a problem, but when I launch WoW and I my patch is fully downloaded, there is always a little bit left... like an inch. This bothers me and I would like it if you made that disappear somehow :)
As said above, there is a section where the Launcher applies certain non critical updates, and leaving the Launcher open for a while should finish this off, however this may take an unspecified amount of time to complete.