The snow is great for skiing. Technology has made oil and gas extraction, movement across the terrian and habitation a much different picture than the historical barrier Siberia represented. Add to it all the other minerals, and China's lack of natural resources and their expanded population, Putin always has an eye eastward.
The illegal immigration in Russia is growing and the Chinese already cross the border in gaps without restriction or documentation to fill low-end jobs. More Chinese construction companies are winning low bids in more regions within Russia.