Netvibes has integrated Meebo into their Ajax homepage service. The Meebo widget lets you chat on all the major IM systems (AIM, ICQ, MSN, Yahoo, etc.) from your Netvibes homepage. The widget is displayed under a tab that notifies the user when a new IM message is received.
Meebo has enjoyed strong user adoption, partially due to schools blocking client side IM applications, among the Gen Y crowd. I also know several former co-workers at Amazon who use it because Amazon, like many corporations, prevents users from downloading and installing client IM applications.
This is a smart move on the part of Netvibes. It helps them tap into Meebo's much larger userbase. For Meebo, this gives them exposure to people outside their core Gen Y audience (e.g. tech savvy early adopters). Although the Dead 2.0 site correctly points out that most browsers (with the launch of IE7) support tabbed browsing and questioned the need for this.