Always follow the money.
MS has to continue to focus on the US because the US remains the biggest non-diversified market in the world. Next, they need to make a bigger push in Europe because it is the 2nd largest market and they have room to grow there. Japan will probably be the last consideration not because its a bad market but because it is the smallest and most expensive to expand into. Devs will go where ever they can make the most money unless they are bought out by Sony or Nintendo.
They should not ignore Japanese style games because those games remain popular here in the US and in Europe but they need to 1st focus on keeping their customers and 2nd expanding into the biggest markets. Popularity in Japan will grow if they can maintain a lead in the US and if they can push Europe into their favor.
I can tell you right now that MS has complete control over the next generation of high end consoles unless a new player enters. They will once again be 1st out of the gate, they are still very profitable while Sony is hurting badly (financially). Next gen will be very interesting and will probably happen much sooner than most expect.







