User blog comment:12th Supernova/Plot Twist/@comment-24850639-20140615164421

Overall storyline wise, I'd have to say the familial connection between Garp - Dragon - Luffy, and the "D." being more than just an initial. It really serves as sort of a central plot twist, because each of them are a major part of all 3 major forces in the world: the Marines, the pirates, and the revolutionaries. Though learning this info didn't solve any mysteries for us (in fact it just created a MUCH bigger one), we know enough to now to know how critical it is to the story of One Piece. The Will of D, this "ancient kingdom", and these ancient weapons are all connected somehow and when shit does hit the fan it will serve as a major plot point for the series going forward (and really already does now).

Some less important honorable mentions:

-Buggy becoming a shichibukai

- Doffy's ability to use "bird cage", and having used it before

- Franky = Cutty Flam, having had the fucking BLUEPRINTS TO PLUTON

- Brook's past as a veteran pirate. More than likely knows a lot more than Oda's revealed, and that his personality causes you to assume he knows

- Learning that Ace had Haoshoku haki too

- The past of the Tontatta; having lived through the ancient kingdom, the void century, the formation of the world government, Montblanc Noland's past, etc.