A lot of times I put my Computer in Sleep mode to save power, but then I remember I forgot to do such and such. I bring it back online and MSN signs back in. A lot of times my status is in "busy" or "away" before I put it to sleep for whatever reason. My suggestions is an option to set it up so your status is changed back to whatever it was before you lost your internet connection. Even if the toast is displayed on other people's windows, it would be a bit more conveniant for the user who lost their connect IMHO.
Sorry if this doesn't make a lot of sense, I'm tired and I'm on mildly sedating muscle relaxants for my back injury