And although the Ospreys wing has no plans to officially confirm his intentions just yet, he does admit that the current campaign is likely to be his last full season as a professional.
"I have to be realistic," Williams, who was a Test Lion on both the 2005 and 2009 tours, told the Daily Post.
"My priority this year is to play well for the Ospreys, be successful with that, hopefully be selected for Wales and then go to the World Cup and to be able to say I've played in three World Cups and to say I've won the World Cup with Wales.
"After that, it's possibly time for one of the youngsters to take the reins and go ahead and enjoy themselves.
"I don't want to be one of these players that carries on playing just for the sake of playing. I know when I won't be good enough to play for Wales anymore, the Ospreys as well for that matter as well, but we'll have to wait and see.
"I've not put it in stone that after the World Cup that's it, but by then there will be a lot of youngsters who are good as me, a lot younger than me and are far fresher than I am and (who will) hopefully go on to have great careers."
If Williams does call it quits in 14 months time, he hopes to be able to do so on a massive high.
Few pundits are predicting World Cup glory for a Welsh side currently ranked ninth in the world but Williamsis confident they can surpass expectation despite the fact that the Dragons have never made it past the quarter-final stages since an appearance in the last four in the inaugural competition 23 years ago.
An unexpected exit at the group stages of the 2007 tournament came as a massive disappointment for Williams and he is determined to make amends in 2011.
"I'm always a big believer that Wales are good enough on their day to beat anyone and I honestly believe that," added Williams.
"In the World Cup you always get some special performances as well, and some big giant killing acts too, and I do believe that Wales are good enough to win the World Cup.
"We'll have to wait and see but New Zealand are easily favourites and are playing some of the best rugby I've seen since I've been playing. But we all know what happens to New Zealand sometimes in the World Cup, so it is just very much just on the day.
"I just hope we go into the World Cup full of confidence and go out there and just enjoy ourselves. Wales are very much like myself really, they play their best rugby when they're enjoying it out there and I hope that's what we take into the World Cup next year."