The main site says that Travis's favourite things are Daydreams. Because of this, it was long suspected that this is his signature, PK [Favourite Thing] ability. And it is confirmed now. It should be quite amusing for Travis to dream up devastation.
Travis's Recovery PSI. As the party leader, Travis obviously has restorative abilities. Interestingly, he seems to be developing Healing before Lifeup, which, so far, only Ninten and Poo had been doing. In Ninten's case, however, it was more extreme, with him getting plenty of levels of Healing before the first level of Lifeup. A question is, is Refresh returning for Travis, or does he have something new? Is he, for a change, getting PSI Magnet? Ninten, Ness and Lucas do not get the powerful Lifeup / PSI Magnet combination, which only Ana and Poo get (And Kumatora, although her Lifeup is not as strong as Ana or Poo's).
Travis, as the party leader, also predictably has these support abilities. What is odd is that he has PSI Shield and Counter, but not Shield and PSI Counter. This pattern was only seen in MOTHER, where Shields were not split into "Physical" and "PSI". It is possible (Although very unlikely) that PSI Shield blocks both physical and PSI moves, while Counter reflects both. Either way, it is an odd combination. PowerShield (Learned by Ninten and Ana) in MOTHER is the second most overpowered move in the entire series, due to permanently making the user (And any party members it is used on) immune to all damage. PowerShield cannot be broken, and it reflects all attacks, making the user permanently immune to damage, and nigh undefeatable. I wonder if PowerShield is returning in a nerfed form for the purpose of blocking both physical and PSI-based hits, if PSI Shield and Counter do not already do this? Because PowerShield is most definitely not returning without being extremely nerfed. It was ridiculous in MOTHER.
Another possibility is that his shielding abilities leave holes. Unlike Lucas, Travis can use both status-inducing and shielding abilities. Ana, Ness and Poo all exhibit this ability, but Travis has the exact status abilities (Hypnosis and Paralysis) that Ness has, and like Ness, some of his Shielding abilities are missing.
Finally, Travis's "Other" category only has Telepathy right now, and it apparently also allows Travis to interact with "psychic objects" (The XX Pillars in MOTHER come to mind). Other candidates for being in the "Other" classification are Teleport and 4th-D Slip.