This thread could also be called "Now that the PS4 has already outsold the XBONE, where does Microsoft go from here? '
Besides, the PS4 hasn't actually overtaken Wii U yet. We don't know December numbers and they almost certainly will put it over 4.2 million. Not that that is all that great for a system that has been out a year longer, just saying.
No. Nintendo has not officially announced any games past February. Mario Kart, at the very least, is likely to release in the next four months. And there is indeed a drought coming for PS4/XBO. In fact we're in it right now. Every system has it after their first christmas, it's not abnormal.