What would have made a difference and probably switch the evolved internet users back to Orkut would the integration of status updates via twitter, friendfeed and any other RSS compatible links.
Primarily, Orkut being very popular in Brazil and India, they should have added some very specific themes which are contextually relevant to Brazilians and Indians respectively. Plus, the usability has also become easy in the sense that a person does not need to wait for new tab or window to open. Personally, i always liked Orkut, since it was the first social networking site that i was introduced to and that time, till date I dont like chatting, so Orkut was a welcome relief to be connecting with friends and at the same time, we dont need to give them instant responses.
Even though, you have the chat facility in Orkut, the video chat may not be all that successful, since we are still facing with low bandwith and the major population who is accessing Orkut, might still be using Dial up, so then the chances of using video chat again, diminishes.
With the new feature, you might just have a slight increase in the usage and interactivity on Orkut, but then a lot of people in groups have already shifted to Facebook and now adopting to Twitter. Dont see all of them shifting or spending time on Orkut, untill they make some drastic changes, not just theme colour. They should also look into adding some more community features and connecting with the people on the communities.