And there you have explained one of the major differences between use of IRC and use of IM. IM is specifically designed to let everyone chat even if they have no computer skills whatsoever. IRC is a more "skilled" level of chat, though over the years it has grown to where many with little computer skill are also using it and that's where you get all of the newer IRC clients that offer these IM style formats... trying to offer that stuff to the users who care more about looks than content. mIRC has always tended to stay more toward the original IRC style (with the addition of scripting of course).
Will mIRC ever try to be more like IM? Perhaps. Though I would be willing to bet that it won't happen anytime soon. Emoticons and other IM types of things have been requested for years and no official comment has been made and those features haven't been added. I'd be willing to be that even if they are on the list of things to someday add, that they are near the bottom. Of course, I'm not Khaled and that's just speculation.
Keep in mind that you can script/program emoticons and other types of graphics displays if you really want to get into it. It's not something quick and easy and takes a lot of knowledge of programming as well as scripting (using DLLs), but it can be done for those that really want it. Of course, the ones who really want it are usually the ones who aren't as computer savvy, so....
Anyhow, like I said, the answer to your question is "Maybe. Maybe not." and that there isn't any official word. No matter where else the discussion goes, that's the only possible answer unless Khaled says something himself.