New Zealand are expected to enter the tournament as favourites having won the last two World Cups and enjoyed an uninterrupted run at the top of the world standings since that latter triumph in 2015.
However, Habana is refusing to count South Africa out following a return to form under head coach Rassie Erasmus and believes that as many as six other teams could be in with a chance of lifting the William Webb Ellis trophy.
"2018 showed a lot more promise under Rassie Erasmus and seeing Siya Kolisi become the first black player to captain the country. From a results perspective there are quite a few things to work on but I think South Africa leading into a World Cup - we're one of those sides that people see as a dark horse and they would want them not to be at their best because they know how dangerous they can be, as we saw in Wellington against the All Blacks in the Rugby Championship last year. [There is] a lot of hard work left in a very short space of time but I'm not going to write off this Springboks side any time soon," Habana told Sports Mole.
"I think given how well we played against the All Blacks in 2018 in Wellington and again in Pretoria - which we potentially shouldn't have lost - that has allowed people to say 'we can't just write the Springboks off'. There's a lot of international experience in terms of games being played in 2019 but, that given, I think the players that were playing well in the group last year, the core group of leaders that will hopefully be in that same mould come Japan 2019 so I definitely think there's time.
"I think the All Blacks will definitely go into this World Cup as the favourites, like they have done the last two or three given they've been the number one side in the world since 2015, given that they're the back-to-back champions of the World Cup. I think what we will see this year is a World Cup that is unbelievably tightly contested and potentially too close to call.
"Ireland probably headed into 2019 as the best team in the world. England have upset the apple cart in terms of their play and potentially should have beaten New Zealand in the autumn last year, Wales going on an unbeaten streak of 12 games... South Africa, Scotland, Australia, they can never be taken for granted so I think it is potentially just too close to call. I think the All Blacks head in with a lot of confidence, but I'm not going to be putting my money on any one team in this World Cup.
"I think the Northern Hemisphere teams have done incredibly well to close the gap post-2015 when you had four Southern Hemisphere teams in that semi-final round, so I think Ireland, England as the number two and three sides in the world have really been unbelievably consistent over the last eight or so months.
"England coming back from a bit of a slump post-2017 and the early parts of 2018 by showing some fantastic promise leading into the Six Nations and potentially to the end. Ireland and their consistency over their last 18 months they've been absolutely incredible, not only on an international level but also Leinster winning the double over in Europe as well so the gap is definitely a lot [smaller]. I don't think we'll see four Southern Hemisphere sides in the semi-final this year which goes to show that rugby is strong globally."
New Zealand will be bidding to win the World Cup for the third time in a row in Japan - having already become the first team to retain the trophy four years ago - and Habana acknowledged that such a run may never be repeated in the future.
"It would be unbelievable. Making it two in a row was incredible, to become the first ever side to win three World Cups in a row would be absolutely historic and potentially unrivalled in the future. It just goes to show the dominance at the tournament over the last 15 years," he added.
"There's a lot to go under the bridge before then, but like I say we could potentially see a new name on that trophy - Ireland have never made it past the quarter-finals. But if New Zealand go on and get three in a row it would be truly remarkable. The dedication and sacrifice of New Zealand to get something like that would be astonishing."
Japan will become the first Asian nation - and the first nation not regarded as a traditional rugby powerhouse - to host the tournament, and Habana believes that it will help to grow the sport even further.
"I think it's absolutely incredible for a World Cup first of all to go to an Asian country and then secondly to go to a developing rugby country that - as you saw in 2015 when Japan beat the Springboks - they deserve to be at the highest level. I think it's incredible for the sport," he added.
"For travelling fans around the world they will experience a culture that's not really been known to the general rugby supporter. It's going to be absolutely incredible. I think logistics might be different to what we've seen in the past few World Cups but that's it. I think Japan are going to be absolutely fantastic hosts and I can't wait to get over there."
Habana won the World Cup with South Africa in 2007.