Highly doubtful.
This game has less going for it.
Super Mario Galaxy was the big and highly anticipated Christmas season game. SMG2 is just a spring release with people not so interested.
Super Mario Galaxy did most of what SMG2 does first. There won't be nearly as many surprises, people know this and will pass on this game as a result.
People who don't yet have the first game, will likely want to play the first game before getting this one.
Review sites are likely to not score this game higher than Super Mario Galaxy; knocking it down a further 500K to 2M in sales (since many couch potatoes who identify as uber-hardcore will be watching that review score, and they follow review sources like wounded nerd-sheep; it might be less because tons of them hate Nintendo more than Republican Americans hate Communism).
Will it be a better game? Very possibly (I would almost say probably).
I describe myself as a little dose of toxic masculinity.
Essay Pro