Wales' 30-3 drubbing of England at an emotion-charged Millennium Stadium meant they retained championship silverware - a feat they last achieved in 1979. Having also reached a World Cup semi-final during the past 18 months, Wales will now target moving to the next level and beating rugby's southern hemisphere superpowers.
"I think there is more to come - that's the scary thing," Wales centre Roberts said. "Our defence is outstanding, there is more to come in attack, and competition for places is very good in the squad. That is what drives us forward as a team."
He added: "When you have got competition like that, you are on your toes and you are only ever a game away from being dropped. That is what drives us forward more than anything - that competitive edge.
"You don't win championships with 23 players, you win it with 35. Guys like (lock) Andrew Coombs, who would be disappointed after losing his starting place after the first few games, have been magnificent in this tournament.
"It's guys like that who win championships, guys who are maybe holding the tackle pads in training and put in the hard work when they're not in the starting XV."
With a neat sense of symmetry, Wales beat England by exactly the same score they trailed Ireland by after 45 minutes in their opening game six weeks ago. Although Wales lost that encounter, despite then scoring 19 unanswered points, they bounced back by winning three successive away fixtures before reducing England to rubble.
Just as significantly, no team has scored a try against them for almost six hours, which showcases the brilliant strategic brain of defence specialist Shaun Edwards.
"Chatting to a few of the boys, if anything it's a better feeling than last year," Roberts added. "From where we've come from in that first half of the Irish game to winning on the road - three on the bounce - and finally delivering at the Millennium Stadium, it's very pleasing.
"We took a bit of a beating from a lot of people after that Ireland game, and certainly the run of results (eight successive defeats) leading up to that. It was a very hard place to be. But it just goes to show the resilience of the boys. Rugby is 90% attitude, and the resilience the boys have shown during the last six or seven weeks has come to the fore."