I suppose it could be Harry's subconscious desire to be loved, manifesting itself in Lily's reaction. He might have seen such a reaction in Molly Weasley's face when she says goodbye to her children for the year at King's Cross, and subconsciously noted it. Just my (admittedly unusual) opinion.

 

I reckon everyone is reading way too much into this. I think, mainly because JK has stipulated that there is an afterlife in her books, that the Resurrection stone brings back a ghost, if you will, of the person, but because they have readily accepted death, and happily gone to the afterlife, to be brought back as a ghost is painful for them, especially as they have seen the afterlife.

 

I'm going to put forth a theory here. Rowling is a bit of a one trick pony- she's got a knack for creating and developing characters, and she has very accessible prose. However, the Harry Potter books are her first real attempt to write a cohesive story. Because the imagery was awesome, the characters were engaging, and the feel was so polished, so many people gobbled it up. They overlooked the underlying problems that do plague her books. These underlying problems aren't because she's an awful writer (or a genius beyond all mere mortals' comprehension) but because she's a rookie writer.

If I had to guess, Rowling basically free-writes her novels and then edits them down into something readable. Because of this, she has a bitch and half of a time ending things, and while each book is readable, the entire series taken as a whole slowly became more and more incoherent. She couldn't ret-con, and because of this the series suffered. A lot.

So my guess is that the Deathly Hallows are actually what I technically refer to as Brainspew. They're basically an idea that Rowling liked a lot, but only conceived of after the fact, so she did her best to shoehorn them in. Like Horcruxes. And Timeturners. If she did conceive of the whole thing in one go, which I will continue to politely doubt, she would have woven more references to Horcruxes, Hallows, and whatnot throughout the story- even if it was only background information.

Power-wise, The Elder Wand appears to be a Rod of Maximize Spell, The Resurrection Stone is an Angst Battery (to fuel young, male protagonists to the critical angst-mass required for wrapping up a series), and The Invisibility Cloak appears to be a self-repairing invisibility cloak. Problem solved.

 

Epic anticlimax :awesome