Heck, one interesting story that could be told in the Harry Potter 'verse is the idea where Harry Potter gets in the habit of carrying a gun with him after, say, Book 1 or Book 2. Then, the first time they meet in person, he pulls it out and acquaints Voldemort with Messirs Smith and Wesson. Alternately, and to make it worse, hold off until Voldemort's return is confirmed; you then have a situation where the wizarding world, one essentially founded on petty bureaucracy and a renunciation of outside reality based on their (legitimate) fears of the technologically- and numerically-superior world of Muggles, is suddenly confronted in full force with the culmination of those fears. If the trio is lucky, the same head-in-sand principles that drove them to deny Voldemort's return originally would also cause the Ministry to reject what just happened and redouble their efforts to keep the wizarding world safe. If they're unlucky, you suddenly have a trio of minors who are using Muggle Artefacts illegally (both by wizarding and muggle laws...how easy would it have been for a child to get a handgun even before the 1997 act?), and even worse, one of them is the child of the head of the Misuse of Muggle Artefacts Office - hello, blatant nepotism in the name of illegal acts. At the least, the entire Weasley family would need to be thrown to the political wolves; at the most, it could bring down a government, especially depending on when this happens, and given the crop of politicians who are up (specifically, the same ones so thoroughly manipulated by Voldemort in the original story), that's not a pleasant option.
Oh, and because of *how* Voldemort's continued survival was assured, specifically since Harry Potter himself is actually a horcrux/phylactery/soul-hidey-thingy, it wouldn't actually take...but no one outside of Dumbledore, Slughorn, and the Death Eaters would know that yet. Heck, the witch hunts that could result would be an ideal climate for Voldy's Death Eaters. It could be the core of a fascinating story, albeit one very different.