New Zealand bounced back from a record defeat in game one at Perth with a resounding 36-0 victory over the Wallabies in Auckland on Saturday night.
A number of players shone for the All Blacks at Eden Park and Hansen believed that could be viewed in two ways.
"A few people really put their hand up last night and where we had question marks, we no longer have question marks," he said on Sunday.
"In other ways, it makes it a bit tougher, too.
"Every time you name the team somebody misses out and it's the end of their dream and this is a pretty big one, going to the World Cup."
Those decisions were imminent, with confirmation from Hansen their squad for the tournament would be named on August 28 in Auckland.
He also confirmed the World Cup prospects of Richie Mo'unga, who came off in the second half on Saturday night with a shoulder injury, were more than likely not under threat.
Hansen said the first five-eighth would be sore for "a couple of weeks" and may miss the September 7 clash against Tonga in Hamilton but explained it was not a long term issue.
Following such a dominant display against the Wallabies, he said they now had just a handful of spots to finalise.
"Joe public could pick a large majority of the team because it's obvious who should be in.
"When it comes down to the last six, seven players and the combinations you want, that's when you get the robust discussions and that's what you should have.
"We'll have plenty of discussions between now and [the announcement] but a lot of the robust ones have been had.
"We've baked a lot of the cake and now it's about in getting it out of the oven and putting a bit of icing on it."
Saturday night's win eased nerves for a lot of New Zealand rugby fans, who were left fretting after a poor performance led to a 21-point loss in the first Bledisloe match.
Hansen said their clinical display was significant with their World Cup opener just five weeks away.
"[It's] massive really because everyone externally was starting to get a bit shaky and starting to question whether the coaches still had it and the players still had it.
"To come out with real intent ..... our nation can now breathe slightly easier and we can all carry on working away to what we're trying to work to.
"What [the public angst] does do is it keeps you honest. The day New Zealand rugby doesn't have the external scrutiny like it does is the day the game is not where it was.
"It's because people care and they have high expectations and those high expectations drive the internal expectations as well."
Meanwhile the All Blacks coach had been left scratching his head after they lost their number one ranking to Wales.
The Welsh side claimed top spot with a 13-6 win over England in Cardiff.
But despite not understanding how his team could win a match and lose the number one mantle, with just five weeks until the World Cup started, Hansen wasn't unhappy about handing it over to the team he once coached.
"Yeah, [Wales] have been great. No problem.
"And now they've got the expectation that their number one in the world so they'll take that into the World Cup. Couldn't be better timing."