As ever in the gaming industry, Nintendo exists in a separate bubble to Sony and Microsoft. Its Wii U is not selling nearly as well as the Xbox One or PS4 but it is certainly clawing its way back, even if it is moving from being an abject failure to just a regular failure.
That is in terms of sales at least; when it comes to quality first party games, the Wii U has bettered the bigger consoles consistently. Not one PS4 and Xbox One exclusive can match Super Mario 3D World or Mario Kart 8, not one. Nintendo's games have always been the sole reason to buy its console and this E3 will be about keeping its recent quality going.