This is in internal testing. I don’t have exact timing for you, but wanted to let you know it is coming!Beth commented
Notifications need a setting so that each user can decide how long they want the message displayed on their screen. Unless a user is pretty much staring at their screen constantly a message can and does get missed sometimes causing unpleasant situations. Businesses and their employees do not want to be burdened with even more emails that are generated because of a missed IM. Please give options as to having the message remain for (ie., 5min, 10,15, 30, 60 minutes) and let the user decide as appropriate for them. Also having a larger and more eye-catching notifier would be a big help, the little change in the circular dot doesn't cut it.