Instant messaging, free calling and video chats made the internet popular. People love to talk. Hotmail, Yahoo, AOL turned out internet media mougal. Whatsapp gone viral it generated sales for smartphone companies.
Google Chat and Hangout did not tasted success indeed it became just another product.
In the coming days more video content will be created, both private and public. Looks like Google now wants from people to spend much time on YouTube. And this is why they have added chat features. It's very basic for now. But personally I feel if more people will start using it, company will add more fun features so you don't need go outside YouTube.
However, technology is still an hindrance. For majority of smartphone users multitasking is not seemless due to slow internet speed and average phone memory and processor speed.
Cell phone prices are going down but purchasing of many people is not moving very fast.
In such a circumstances it's not pretty easy to say if YouTube messenger will catch wildfire like Whatsapp or Yahoo messenger. However if smartphone makers will be able to provide more for less and ISPs real high bandwidth then more people will hangout on YouTube for productivity and fun.
Taking control of three things is extremely difficult specially to those who are habitual of grinding smartphone screen; 1. Time 2. Data and 3. Battery. Data will be costly in coming days, sooner or later, but this will happen. There shall be campaign to save data same like today there are campaign to save water, electricity and food.