Sorry, but I don't believe that Harry will ever get a Warden's sword. It seems to me that Jim is purposefully holding Harry back from wielding any sword. Considering Harry's slow but steady change of opinion in regards to God, faith, his devotion to Magic, the fuzzy undefined nature of the White God in the Dresden Files, and his respect to the Swords - not to mention Michael's subtle actions indicating that he believes Harry could be a wielder - I personally believe that Harry will one day be put in a position in which he's forced to take up the Sword of Love, and thus discard one Mantle of power for another. He's being prepared for it.
Yeah, it's currently a huge stretch for his character, but that's the fun thing about predicting things that will happen in the Big Apocalyptic Trilogy. If a halfhearted Baptist, an Atheist, and a Jew can be a Knight of the Cross, then I don't see why a wizard can't.