It'll be curious to see how Claremont handles Gambit and whether he's revealed to be the Third Summers in this continuity. He's already stated that he's quite happily ignoring revelations made after he left the book and he has done so already. So we might see those original plans for Gambit - my guess is that he will be the third Summers brother - but through Sinister's cloning of Scott and Alex's DNA rather than any natural birth.
Anything that retcons Vulcan out of existence gets my vote.