Clearly the game can't be 100%'d until you get all the milestones. I'm still around 998,000 matches from clearing Melee completely (although that still might happen before I get all the stickers in Brawl).
Seriously, though, I think 100% includes all unique collectables (Mii wear, custom moves, trophies, CDs) and challenges (hammers optional). "Any%" doesn't really make any sense, IMO. Not that 100%-ing Smash is at all necessary; I plan to do it and enjoy it, as I did twice with Melee, but I had plenty of fun with Brawl and its mods without ever getting all the trophies and stickers in Brawl.