World of Warcraft 4.0 patch downloading questions? help?

Okay so i started downloading the patch4.0 and it gets to this part where it Says Blizzard Updater. its really slow. But i look at the files is downloading and its all files from Normal WoW Like "Installing Human Face" or something. Is this normal? Once i finish the Blizzard updater is the patch fully done? Fill me in please :)