As for Bottles explaining the moves--I think that would be a really awesome and cute gag, though let's not forget their Direct would have to convey that information in a way most people will be able to follow (audio and visual cues). It'd be a fun nod to the fans, but if it went on for too long, it would turn off the vast majority of other people watching. I think it would be a nice funny gag for a couple minutes, before Sakurai comes in to explain the moves more thoroughly.
My ideal Direct: Open with Smash 64 opening, Master Hand drops Yoshi on the table, goes to the countdown and stops at 1. We see Banjo and Kazooie in their N64 come out of the chest, followed by some gameplay. Sakurai goes over their history and moves, including showing off some new mechanics, followed by a gameplay demo. We see Spiral Mountain in action, and pays extra attention to that. He goes over the music, if not the largest music selection of any character, than at least of DLC, mentioning Grant Kirkhope's contribution. If Grunty is a boss, he goes over that and how best to peck the witch's butt, similar to how he described Dracula in Simon's trailer. We then go back to a more Direct style where it shows off Mii costumes, including B&K and Microsoft characters. As well as new modes--if Grunty is a boss, a boss rush mode announcement would be nice. And then an announcement of when they will be released.
I don't think that's going to happen--unfortunately, I think Hero was the exception. But it would be great to hear directly from Sakurai--I felt like Joker's was a lot more sterile with his absence.