The short length (three chapters) is not all that surprising given that we're supplied with an incarnation of SuperHarry right from the beginning. Seems to me it will be more about how Harry's various relationships would have changed had he asserted himself early on, not at all a bad starting point for a tale.
That's one of the things that drove me crazy with canon. Harry starts out with greater than average powers; accidentally Apparating as a child, facing down Quirrel as an ickle Firstie, defeating a Basilisk and rescuing Ginny second year, conjuring a Patronus and chasing off over a hundred Dementors as a third year for Chrissake! And then throwing off both Crouch's and Voldemort's Imperious, and duelling Voldemort wand-to-wand and winning! (Even with the limitations of brother wands, forcing the spell back into Voldemort's wand has to count as a win on the pure power conflict!)
And then after fourth year it all starts to dribble away, to the point that by seventh year he's a weak, virtually squib-like dweeb who can't stop making stupid mistakes and has to slavishly follow Dumbledore's plans even after the geezer's dead, and is so brain-dead he saddles one of his poor kids with the name Albus Severus. Is he trying to create the next dark lord?
Anyway, hopefully this newly awakened and empowered Harry will grab the bull by the horns (and the babes by their robes) and get out from under the thumbs of meddling heamasters and the sights of psychotic Dork Lards.
Perhaps the three of them could run off to Acapulco or Cabo San Lucas afterwards; Harry could go as the Dark Lord Valdez, with Hermione and Luna wearing t-shirts that read "There Can Be Only Juan"....