Describing the tournament as "a long haul," the Corkman is relishing the opportunity to secure Ireland's first championship success since 1985 and he feels Ireland have the ability to kick on from their stunning performances in the Guinness Autumn Series.
"We set ourselves a target of improving in the autumn. I keep telling people that we can't stay where we are. You either get better or you get worse. The option for us is to get better and we can certainly do that.
"The Autumn Series was very good for us and I'm not trying to play it down, but we still feel there was room for improvement in certain areas and that's the challenge for the Six Nations," he said.
With confidence high after those November wins over South Africa and Australia, O'Sullivan knows teams will extra motivated to get one over the men in green, and none more so than Wales, who lost 31-5 in Dublin last year and could hijack Ireland's title bid in Cardiff on Sunday week.
"I think Wales are a side sitting nicely in the background, deflecting attention but quietly confident that they can cause mayhem again this year," O'Sullivan admitted.
"I think Gareth (Jenkins) is going to mould his team around the strengths of the side. In recent seasons, we've seen a Welsh style of rugby that has emerged. It's very much a 'quick-hit-and-run' game. They can do that with the players they have - two very good half-backs, who can control the tempo of the game, good ball handling forwards and line breakers in the backs.
"They'll play a 'run and gun' game. They seem to play it at a hundred miles an hour in Cardiff. It's our first game and I don't see Gareth changing that too much."
A key word for O'Sullivan's charges, as always, will be 'control.' Assert themselves at the Millennium Stadium and a winning start should be theirs.
Although admittedly "comfortable" with his side being judged as favourites, O'Sullivan was quick to point out that "it is just an opinion - people have seen us play and have given us a shot.
"It's a good place to be," he added, ahead of his sixth championship in charge. "You just have to rewind twelve months when we were not expected to do so well. It's just a case of us not worrying about it too much, and focusing on what we can control, which is the way we play ourselves, and set a target on improving on the performances in the Autumn Series.
"We've got to keep our heads down and get on with it. Make sure we hit the ground running in Cardiff."
O'Sullivan was also keen to point out the benefits of the Six Nations tournament, particulary with September's World Cup in mind.
"This tournament is really the best rugby you can play in this part of the world. We have the Southern Hemisphere teams coming here in the autumn, we go there in the summer, but it's not the same thing.
"Six Nations rugby is incredibly intense and hugely pressured. If you can deliver a consistency in performance in this environment, certainly it will stand you in very good stead for next autumn."