>Browsing and chatting simultaneously is cumbersome and inefficient now, as you need to switch between tabs when responding to a message
Or, since we all have widescreen monitors (and often multiple monitors) you could just have your messengers in a window next to the browser instead of a sidebar within the browser. Seems like a solution looking for a problem. What good is allowing messengers to reside within your browser other than that it lets the people who are tracking your browsing habits simultaneously spy on your messages?