At E3 I would LOVE a new trailer with more gameplay or some story elements. But even just an official title and PLEASE PLEASE PLEASE confirm that it WILL be released worldwide without being delayed 2 years in NA for localization.
As for the game itself (some of the things I'll mention are already clearly shown in the trailer):
-Huge, open-world, diverse environments for exploration and sidequests (confirmed in debut trailer, except for the diversity part...hopefully lots of HUGE areas like the one they showed but with different themes and environments like Xenoblade)
-Epic soundtrack (confirmed in trailer, even if it's not the same team that did Xenoblade's FLAWLESS soundtrack, if they can make a full soundtrack of great music like the trailer, I'd be thrilled)
-Vibrant, colorful areas (The game is still in development, but this was my only concern from the trailer. The increase in "realism" thanks to HD and higher resolution textures tends to bring out more BROWN in games, just look at the majority of PS3 and 360 games, no offense but a lot of them are brown...anyway, I just hope they still use plenty of color and vibrancy...though what I saw in the trailer was still beautiful, AND THAT DRAW DISTANCE...drool...)
-Keep Xenoblade's battle system with real-time, arts-based action (Confirmed in the trailer, even with Chain Attacks confirmed to return, AND with the ADDITION of swappable weapons. In the trailer the black-haired male switches from his sword to a gun mid-battle and his arts change to reflect that, awesome!)
-An EPIC, long, multi-faceted story like Xenoblade's
-British voice acting again, please. (I wasn't a fan of voice acting in games until Xenoblade as most Western games with American voice acting just seem cheesy because CGI or character models can't quite match the subtleties of real human expression regardless of how good the voice actor is. Not that British voice actors are better, but it just gave the game a different flavor and feeling...it was cheesy at times still, but it felt appropriate and then other times managed to be very powerful and meaningful)
-Memorable characters (Xenoblade excelled at this as all of the characters were unique and well-defined in both personality, looks, and in the way they controlled and fought.)
-Continue mixing, comparing, contrasting the Natural/Machine elements (Basically confirmed in the trailer with the addition of Dolls you can fly, travel, and battle with)
-Keep fast travel (With such a HUGE world, Xenoblade letting you freely warp to any landmark that you've taken the time to explore, find and visit was brilliant, even if there wasn't a good explanation of "why" you could. Maybe explain it as teleportation. They could also be planning to alleviate this a bit with being able to fly in the Mechs, but that could backfire if you're constantly running out of fuel)
-Keep the auto-levelling of characters who aren't in the active party (I loved that regardless of who I fought with in Xenoblade, the other party members levelled up right along with them. Saved me the frustration of having to grind each character...Pokemon's biggest flaw in my opinion lol)
-Keep the Gem/Affinity/Skill/Skill-Link systems (But maybe make it easier to increase Regional Affinity without having to do nearly EVERY sidequest)
-Improve the inventory management (More options for organization and better menus)
-Improve the Tutorials (It took a lot of trial and error for me (as an JRPG novice at the time) to figure out how to use Melia properly. The tutorials weren't much help, but after a little online help Melia became my second most-used character after Shulk once I figured out how her spells worked as buffs before you unleashed them as actual attacks)
-Still make it possible to play the game single-player and have A.I. party members (They're clearly implementing a Monster Hunter-type online system with chat and up to three players in a party, but please make it optional to play the game by yourself. I'm a little concerned that you won't be able to have party members without actual players to control them and that it would affect the flow of the story and the characters' hopefully distinct personalities)
Those are the specific things I loved from Xenoblade or want in X, but other than that I want them just to craft another lengthy, epic, beautiful adventure that I can lose myself in for another 100+ hours. I put 150 hours into Xenoblade and it has never been such a pleasure to side-quest for hours and to grind to lvl 99. Make this the game that makes people who aren't interested in "another Zelda, another Mario, another Smash Bros., another Metroid, etc." STILL want to get a Wii U. It has the potential. Definitely my most hyped game (until they show the first screens or footage for Zelda Wii U :p then it'll be tied).
Upcoming Games To Get
Definite: Kirby Star Allies (Switch), Mario Tennis Aces (Switch), Fire Emblem (Switch), Yoshi (Switch), Pokemon (Switch), Kingdom Hearts 3 (PS4), Monster Hunter World (PS4)
Considering: Fe (Switch), Donkey Kong Country Tropical Freeze (Switch), The World Ends With You (Switch), Ys VIII (Switch), Street Fighter V: Arcade Edition (PS4), Kingdom Hearts 2.8 Remix (PS4), The Last Guardian (PS4), Shadow of the Colossus HD (PS4), Anthem (PS4), Shenmue 3 (PS4), WiLD (PS4)