I wonder what happened to the Blonde St Germain. I assume everyone else went back to normal, but it was implied she'd been surgically altered to look that way. Must have been pretty freaked out to wake up looking like a different person.
They said that Railgun 3 would only happen after Index 3, presumably to stretch out its lifespan for as long as possible, because it's literally impossible for Railgun to outlive Index. Not unless they prepared a shitload of filler, possibly more filler than any other show has ever had.
Not cool man. Not that the series was good enough to ask for it to continue but still it would be nice to get another season just to wrap things up at least a little better.
So, Index III would have the C-Document, Battle Royale, Acqua and probably the Stiyl SS since that introduces Birdway. Maybe one episode centered around SS2.
Index IV would have the plane hijacking, British Halloween and WWIII.
New Testament I would have Freshmen, Radiosonde, Hawaii and Baggage City.
New Testament II would have Ichihanaransai, Agitate Halation and Othinus.
New Testament III would kick things off with Shokuhou, followed by St. Germain.