Too early to be exact. Last time we had a dojo who did it's job on character revalation. The inclusion of Neku could be possibly from Kingdom Hearts 3D: Dream Drop Distance which spiked the character's popularity, that and almost everyone has played TWEWY.
No signs of Mega though, I did recall sakurai wanting a capcom rep, didin't mention who but this is one of those wait and see games. Samus is fine the way she is though, a nice, balanced character with the Zero Suit form being speed-based, rather than the varia suit, which is balanced and has been so since 64.
Removing F-Zero and Mother characters would most likely receive possible backlash from tournament players. Sure, Lucas still has a chance of getting tweaked to seperate him from Ness, but I doubt Capt. Falcon and the Mother crew would fade anytime soon, and the Captain is an internet favorite.
Konami obviously might be getting Belmont, the second most well known character to Snake in the list. I have no idea if this is confirmed from the Konami side, but again, it's a game of wait and see.