Aside from Danganronpa, Great Edo Blacksmith, Stranger of teh Sword City and duo of Spike Chunsoft samurai games are best bets.
I also expect them to localize Kadokawa/From Software unnamed titles for Playstation systems, since NISA is in good terms with Kadokawa. Maybe they'll localize Kancolle Vita too.
Don't get me wrong, because probably my most anticipated localization announcement for years is DanganRonpa: Another Episode (and I'd be all over SoSC and Ukiyo no Roushi if they were localized), but none of those would be "biggest announcement yet".
I mean, NISA localized Bleach in the past, so I'd assume from a quote like that we're talking something more of that scale. DanganRonpa is something you'd expect them to pick up given fan reaction to it. Great Edo Blacksmith is the usual stuff they localize because it's made by N1.
The Kadokawa stuff is interesting, but seeing as how none of it has released in Japan yet (and we haven't even seen gameplay for most of those titles yet) I don't think we'll be seeing them at this press conference.