Haven't been to the forums in a while... it's been busy!
I've given more thought to Mii characters as playable fighters - I can't imagine that they wouldn't be unlocked from the start. Unlocking Miis means unlocking the menu to set up Miis to nametags, etc. To hide that menu at first and make it come up later seems counterintuitive.
I'm loving the daily updates though, and today was no exception - I'm really happy that stickers are not replacing the awesomeness of hundreds of trophies. But what I'm really blown away by is the sheer depth of the game. Ten extra characters added to the roster including the three pokemon, (that we know of), stickers, trophies, more music, new stages, a full-fledged one player mode, online modes, and more still being announced...
It's going to be just like Melee - a top seller and system seller for the next five years.