My bet is:
Konami recently registered the trademark "Contra: Run and Gun".
http://www.gamespot.com/e3/konami-seeking-contra-run-and-gun-trademark-6409503/The title suggests a "simple" game, stylish smartphone/tablet. In a recent interview is interesting to see how MS chief talk about next project. He uses the word "device", that word struck me, in Spain not usually use that word to talk about consoles (they are called "consoles" or "systems"), that word is used for smartphones and tablets.
If we add this to the known interest of MS and Cox to resurrect the franchise "Contra" ... We could have a resurgence of "Contra" on IOS, Android, Live, Plus (and perhaps portable consoles)?
It seems that Konami is now very interested in "simple" games for iOS and Android devices, also Square/Enix is launching and will launch many new games for these formats.
Nintendo itself commented recently that had arisen launch their games in these formats but so far ruled out because the gaming experience would not be the same (as the 3DS is selling well .... we'll see in the future)
According to statistics over 60% of the gaming market in Japan now is in portable devices (iOS, Android, 3DS, Vita), that is the reason that both Sony and Microsoft do not sell from the beginning their consoles in Japan, not a priority market and Microsft has nothing to do in Japan ... so no battle. The battle is in Europe and USA.
These are just my theories, nothing more.
Edit: In the same interview, MS confirm that his new project has nothing to do with Castlevania, also said that will "cambiar de registro" (I don´t know the expression in English), it will not be a Hack & Slash... another style.