This E3 proved to be elusive for a Final Fantasy XV announcement, but Square Enix haven't been silent about it. In an interview with EuroGamer, FFXIII producer Yoshinori Kitase made it clear that FFXV will remain on a high-definition console.
"If you're talking about the main Final Fantasy titles, one of the strong focuses of the series is cutting edge graphics. That's what people enjoy and that's what people associate Final Fantasy with."
"In that sense I would like to assure our users of this top quality artistic visual achievement. To do that we have to stick with high definition consoles."
Kitase further commented that Square Enix will continue concentrating on handheld development for Final Fantasy spin-offs, such as Crisis Core:
"Though the main Final Fantasy franchise has always been with top definition consoles, Crisis Core, for example, has been very successful on PSP. So those smaller projects we'll consider for PSP2 or 3DS."
Source:
EuroGamer