A few Fire Emblem 3 Houses Thoughts:
Sales: I see a few people overestimating Fire Emblem here. Don't get me wrong, it is probably my favorite franchise, but people predicting upwards of 5M sales are very optimistic. 3-4 Million would be outstanding & blow away any other FE game previously released. I understand there will be a Switch bump & FE heroes on mobile will bring in some new people, but Turn Based Strategy JRPG is still relatively niche.
Delays: As for the people concerned about FE 3 Houses being delayed again, I highly doubt that. The trailer was actually pretty full of content that teased story whil also showig off actual gameplay. They probably felt it was far enough along to show off like that. Combined with Nintendo confirming to investors that it is still currently slated for Spring, I have faith.
Story: I'm really liking the initial story they're teasing. It seems like they're trying to bring back some religious overtones to the story, which was a big part of what made the Tellius games story so intriguing. My guess is the 3 Lord Characters are nobles from allied nations kind of like FE7 had Eliwood from Pherae, Hector from Ostia, & Lyn from Sacae all as part of the Lycian League. Then Byleth (a lot of people are referring to him as an Avatar character, but we haven't been any reason to believe that yet) I am guessing is an instructor at a Military Academy of sorts, based on how Edelgard refers to him as teacher consistently throughout the trailer, and asks him what she should practice for their "Mock Battle" as well.
Other Notes / Gameplay Mechanics: I like the look of the formations, & I'm curious if they will also follow a Rock-Paper-Scissors style mechanic like the weapon triangle. Speaking of the weapon triangle, I am ready for them to bring back Light, Dark, & Anima magic & the Magic Triangle along with it. I need to cast Flux & Luna again! Finally, I am personally hoping that they don't go too crazy with the child mechanic in this one because I feel like it tends to bloat the roster a bit, but I understand it's popular to some people. I'd just rather it not be shoehorned in like they were in Fates.
Final Thoughts: Hype levels are thru the roof, & yeah, I can't wait for Nintendo to drop a direct so that I can get more info or a confirmed release date. At this point I'm thinking it will be a May release, as there are a ton of 3rd party games to compete with in April as well as the Fire Emblem expo. Really we just need the Direct because the Fire Emblem fanbase is crazy & will freak out by assuming delays / multiple SKUS / avatar characters / children, etc until they're confirmed or deconfirmed. Here's to hoping it ends up being one of the best in the franchise.