One problem that arises with this suggestion is nick length. Many networks would not support that length, particularly for people who already have reasonably long nicknames. mIRC also cannot display an /away message like some Java clients might (i.e. with features like 'Do Not Disturb') for a number of reasons (e.g. not everyone uses mIRC, none of the information is obtainable from the server without a /whois, and away messages can change, so mIRC would constantly have to /whois everyone in a channel).
It's simply not practical to implement this, as far as I can see. This is a mere variant of the suggestion to change people's nicklist colour when they are set /away.
Regards,
