I've downloaded the new client for The Wrath of Lich King and when the patch installs i get this error:
The file "H:\game\Wrath of the Lich King 3.3.5a\Data\enUS\speech-enUS.MPQ" could not be renamed to "H:\game\Wrath of the Lich King 3.3.5a\Data\enUS\speech-enUS.MPQ.Trash". If this problem persists, please contact Blizzard Technical Support. (ConflictManager::ResolveConflicts/3)
To check this installation for problems, click the "Repair" button. The Repair tool can automatically fix many update errors.
your client is ready to play, you do not need to install anything.
That message happen when someone use an email to log-in and as I told you on Warmane you need to log-in with AccountName in game