Next weekend Wales need to beat Italy by a clear 18 points more and conceed less than 5 points than Ireland conceed to Scotland, to avoid having to beat Ireland by "x" amount instead of just a win, to take the Six Nations championship.
France are also still in the running for the championship and need to beat England and Italy by 20 points more than Wales beat Italy and Ireland and conceed no more than than 9 points than Wales do against Italy and Ireland to win the championship.
(er...I think I've worked it out right
).
A bit optimistic 
Well, last year we beat Italy 47-8, so not too optimistic, but Irelands 38-9 win over Italy this season was very flattering to the Irish. The score didn't reflect the game at all. Italy lead until 1 minute from half time.
Then again, Irelands 14-13 win today should have told of a cliff hanger of a game, but it was a poor game. O'Gara's kicking wasn't on form at all.
Either way, if we get a good score line over Italy then the Wales v Ireland will be the Six Nations and Triple Crown decider.