Conjecture will jump into some substance as evaluations and discussions spread about the chances of teams later this year in Japan.
Ireland, Wales and England fill three of the top five current rankings for that event and while the All Blacks still head those rankings they were knocked over by Ireland late last year after squeaking home by a point against England.
All bets aren't off for the World Cup but the margins have shrunk.
They have won their last dozen tests in Dublin including their 16-9 win against the All Blacks.
Ireland cannot hide from the glare, they have to deal with favoured status. They have won their last dozen tests in Dublin including their 16-9 win against the All Blacks, are the reigning 6N champions and under Joe Schmidt's coaching drive have risen to second place in the global rankings.
Their pack is formidable at set-piece, breakdown and driving interplay and they play with a disciplined tactical belief while a fit Conor Murray and Johnny Sexton control the tempo of their plans.
England will fancy their ability with the Vunipola brothers in the demolition business and Maro Itoje to spread his skills in the heavyweight forward contest where the influence of former All Black coach John Mitchell will come into focus. Behind that crew the tactical work of Owen Farrell and his goal-kicking will be a prime feature in the England arsenal.
The uncertainty for England will be about their comfort with the ball and how they respond if they fall behind on the scoreboard. Do they have more than one style in their kit-bag and can they find their tempo away from the comfort of Swing Low and the capacity audience at Twickenham?
That prospect is absorbing and so will many more threads before the tournament finishes in mid-March.
We'll know if Schmidt, Warren Gatland or Eddie Jones has overseen a 6N triumph and how their sides have played and responded to adversity.
We may not be any firmer in our views on their World Cup threats but you can be sure southern hemisphere coaching strategists will pick over the Six Nations tournament intensely and some may travel to watch games before they concentrate on the closing stages of the Super rugby series.