Yeah, that sounds like a great feature! The number of times I got the update notification, went to the homepage to download it, and then...left it sitting in the download folder because I did something else is greater than zero for me.
I do like that I can just install the new version while mIRC is running and be up2date next time I run it (pretty much next day for me; I'm not one of those maniacs that keeps their system running 24/7.)
Hope the updater has the same feature and doesn't force me to restart mIRC or anything once it is done.