It's a tough call because we don't know if MS will bring the price of the X1 back up to $399 or not. We might see the AC bundle priced at $399 and the standalone console at $349. However, even then, I don't think that will help that much. The PS4 has a lot more exclusives in 2015 and the lineup will likely be bolstered with more unannounced games. And of course, Sony still has the $100 pricecut in its back pocket while MS has already made several soft pricecuts.
As for China, the PS4 will definitely do better than the X1 over there. However, I don't think it will contribute that much to 2015 sales. It's a boost nonetheless.