I will believe it when I see it, frankly. I suppose there is some evidence to say it is going to happen, but there is a world of difference between "sources say" and an actual announcement, and Putin has been in power for a very long time.
If he's going to groom his successor I can't imagine there will be much of a change in Russia's relationship with the rest of the world unfortunately, but whoever they are, they won't be Putin, so who knows. I'm not especially knowledgeable on the ins-and-outs of Russian politics!