Man, I don't think that Nintendo has ever given this much hype and advertising to one of their video games before. They are really hyping this game up and advertising it really well. Heck, they even said that they will continue advertising this game throughout the entire year even after the game is released. That right there shows how much much Nintendo is really is trying to make sure this game becomes a success and sell millions of units along with Smash bros 4. I hope Mario kart 8 sells  just as much units as Mario Kart Wii has over the years.

so far nothing confirms that all of what we saw are the full roster....other characters might appear as unlockables

 

Yes as there is 6 character slots still yet to be filled in

I hope you're right about that

I hope you're right about that

me too,most likely they'll be unlocked by completing cups and Time Trials

I hope you're right about that

Well if you check Wikipedia there are 6 slots that need to be filled in. Also Nintendo released pretty much tons of information about the game already, if there smart they won't release all the information in the game as it might make people upset and not want the game; you would be surprised how many of my friends didn't buy MK7 because they revealed all the characters a month before it's release.

https://www.youtube.com/watch?v=VrrBZ1W4kSkGet hype.