Following some digging, Siliconera have discovered two new trademarks recently filed by The Pokémon Company International under the names 'Pokkén Fighters' and 'Pokkén Tournament'. A similar trademark was later established in Japanese for the core term 'Pokken' 'ポッ拳' by AAPF. The name, odd as it may be, essentially breaks up into 'Poké' (as we're all familliar with) and the Kanji for fist - probably most recognisable in the Namco Bandai fighting game, Tekken (Iron Fist). Speculation has arisen that the trademarks identify the game teased at the end of the Pokemon Game Show nostalgia bomb trailer, though both the trailer itself and any imagery/video of the game in question have yet to be officially revealed to fans outside of the X/Y preview event in Japan this past weekend. The noticeable presence of the TCG's Fighting Type symbol surrounded by typical tournament/championship ornamentation in the background of the preview clip paints a good picture that the two are indeed related.
If so, it may well mean that instead of a new Wii U Battle Sim game to follow on from Generation IV's Battle Revolution, the teased game is, in fact, a traditional fighting game starring fighting type Pokemon. There is, of course, speculation that the similarity in name to Tekken may well mean Namco Bandai themselves are involved - or that there could actually be a cross over point between the Pokemon franchise and Tekken (it wouldn't be the first curve ball cross over for the series) - though the name similarity is also possibly just a coincidence, as the literal translation of both Pokkén and Tekken is very much reliant on the generic word 'fist'. Something that might stand out a bit more in the West, but is essentially the same as adding the word 'Fighter' for Japan - an event that similarly wouldn't necessarily confirm any involvement from Capcom in that case.
Regardless of who is developing the game (which remains a salient question, regardless of the relation to Tekken), fans have been seeking something along these lines for a long time - with many expressing a desire for a version of Super Smash Bros. dedicated to Pokemon. This may be more of a traditional fighting game than party madness of Smash Bros - if it is one at all - but there is definitely a lot of potential for creating a fighting game of any style with the wealth of appropriate characters Pokemon has to offer. The variety of fighting types alone would secure a varied and vibrant roster - and there are enough human shaped Pokemon that aren't fighting type that you could expand even further, as well.
Nintendo and The Pokemon Company are clearly gearing up for an official reveal of the game, and we expect it to be within the next few weeks ahead of X/Y's release. Whether the game will release this year is uncertain, and probably unlikely, but whatever happens, it looks like it might be one to watch out for - and could be a major player for the Wii U amid Nintendo's other current efforts of lazy sequels and quick remakes if it does turn out to be a whole new spin on the Pokemon franchise.