They have been doing it this entire gen.
Not really to any great extent, most of Bayonettas sales were in Japan were they not? Being X-360 exclusive would kill the sales potential of the game.
Other than Blue Dragon, which flopped compared to what it could have done, and made no headwind for the 360 in Japan, and infinite undiscovery have they done?
If anything these failures make it less likely for MSFT to pursue that in the future, the MS brand is hopeless in Japan, I think they've realized they are better off dominating America.
Nintendo is king in Japan, MSFT is better off letting them spend their money in the home country instead of trying to poach Western stuff away from them.