Hyphenation is not displayed properly in konsole, rxvt, gnome-terminal, ... when the "ar_SA" locale is used to display a man page or using the less pager Bug 6479. This thread seems to be related to the bug.
Deleting Arabic text in terminals in response to an interactive command using BACKSPACE will delete the question itself!
When you type any interactive command in the console (e.g. rm -i), you will be faced with a question such as:
rm: remove regular file `filename'? |
Now, if you switch to Arabic and type some Arabic letters then BACKSPACE to delete them, you will delete letters from the question itself which is equal to the number of the typed Arabic letters. Looks as if something concerned with Arabic being double byte and the UTF-8 encoding. This problem is in konsole, xterm, mlterm, gnome-terminal, ... Bug 5645 (update: if you type any Arabic letter in a shell's prompt, you won't see it, this happen in all of them except gnome-terminal, try to discover where has it gone ;) )
Trying to type any Arabic text in konsole (kdebase-konsole-3.2-70mdk) will type nothing. It's a font issue. Settings -> Font -> Custom -> Ok without changing anything will display the Arabic correctly. Why not from the begining then?