But things didn't quite go to plan as Eddie O'Sullivan's men found themselves on the first plane home following defeats to France and Argentina.
It was a sobering experience for all involved but Leamy believes the seeds of their failure were sown before the tournament began.
A lack of match preparation in the lead up to the competition left Leamy and co undercooked, something the Munsterman believes cost his country dear in the end.
"We prepared really well in 2007. We had a great pre-season and were in really great shape. We just weren't battle-hardened enough in terms of matches," Leamy told PA Sport.
"Before I'd played my first game in 2007, I'd been on the pitch for possibly 30 minutes.
"With the number of warm-up games we have now, lads could have possibly three to four matches played this time. For me, the big difference this year is that when the first ball is kicked against the USA, the boys will be battle-hardened and up to speed in match fitness."
Ireland begin their World Cup warm up matches against Scotland at Murrayfield this Saturday, before back-to-back games with France and a fourth and final clash with England in Dublin on August 27.
Leamy is convinced that the hectic schedule will be a major benefit when it comes to the tournament itself but he also believes that the way in which the squad are publicly assessing their hopes and aspirations also gives them a better chance of succeeding in New Zealand.
Prior to the start of the 2007 World Cup, all the talk in Ireland was about the latter stages, reaching the last four and possibly competing in the final.
This time around things have been different, despite a Grand Slam in 2009 and an impressive win over England in their most recent fixture.
"The pre-season training has been difficult, but getting match fit is completely different to anything else," added Leamy, who will be hoping to become a regular starter once again having seen Jamie Heaslip, Sean O'Brien and Stephen Ferris all star on the blindside or at No8 in the last two seasons.
"We probably didn't play too many warm-up games in 2007 out of concern for injury. Geordan Murphy didn't make the 2003 World Cup because of an injury and it's a difficult balance to strike. Injury is a risk.
"The last few weeks have been very intense. It's been pretty exhausting and any spare minute you have, you put up your feet, relax and take it easy.
"You enjoy this time in a sick way. It's a challenge and you have to try to get through the pain. Your muscles are aching and screeching at you to stop.
"It's a good test of your mental strength and it's satisfying when you come out the other end. We've had some really tough sessions with guys spewing up their dinners and stuff like that.
"We're better off moving on from 2007 because it was so disappointing. There was such a big build-up and it didn't help that we openly stated we want to reach the semis and final. When that didn't happen it was used as a stick to beat us with.
"This time it's all about getting out of our pool. We can start to dream from there."