Do you mean growl popup notice?
As people might be know, Web Notifications (http://www.w3.org/TR/notifications/) are similar to how Growl displays its notifications, but are very different in most ways. You can see them in Safari 6 and Chrome today. In OS X Mountain Lion, notifications appear in the new “Notification Center” (http://photos.appleinsider.com/notificationcenter_hero1.jpg — the grey vertical column on the right). I believe they will also appear in iOS 6’s existing notification panel, but I haven’t tested that.
I don’t know if Web Notifications support will be added in the *next* version of BuddyPress, but I’m going to try to get them into a future version of BuddyPress. I’m actually playing with some implementation ideas for another plugin that I am working on, so by the time it comes to BuddyPress, it ought to work nicely.
