I tell ya, parents probably wouldn't be anywhere near as thrilled that their kids were reading Harry Potter if it was imagined by George RR Martin.  But some parents out there weren't thrilled their kids were reading Harry Potter anyways.  There's actual legitimate proof that some people just can't let books be great.  Motherfuckers.
  Seriously, I was allowed to read pretty much whatever I wanted by the time I was old enough to comprehend the written word.  Anne Rice, Stephen King, Kids Who Kill, The Skin Trade... my mom was down as long as I was reading.  But there was a small pile of books I wasn't allowed to read.  It was the Sleeping Beauty Trilogy by A N Roquelaure, which my mom kept in the cubby of her headboard.  And what did I read any time I was left alone in the house?  Yeah, not the phone book, that was for sure.
  My point is, let your kids read whatever the hell they want.  They wanna read Shakespeare?   Have at it.  Hardcore pornography?  Don't make a big hairy stink about it, maybe let them know that the stuff they're reading isn't an accurate representation of the world around them (hell, you should do that in general) and trust the fact that you progeny aren't idiots.  Because if you tell them they can't, you'll be damn sure that's all they'll be doing when you're gone.  And if you catch them reading Sailor Moon fanfiction?  Pray for their very souls...