The Audio books are great. Roy Dotrice (sp) is the guy who reads them and he has a really nice take on things. He had a cameo in Game of Thrones Season 2. He was the Pyromancer who dealt with all the Wildfire stuff, gave Tyrion the torch to throw as the signal for the Blackwater episode etc. Audio books are too slow for me though, as you can read internally like 10x faster than you can listen to someone read aloud. I read the newest book Dance with Dragon in 4 days. It would have taken over a month to do it with the audio books. I need to know what happens WAAAY faster than that! =p
And Season 4 isn't actually book 4. Season 3 was only HALF of book 3, Season 4 will be the second half, though I'm sure they will start to touch on some of the events from book 4 Feast for Crows.
And the books go far beyond "a little" more detail =p. There is an enormous amount of information you do not get in the TV show. I've read the series 4 times for most of the books (I re-read from Book 1 each time a new book comes out), I pick out new stuff every time I re-read it, stuff that makes me say "How could I have missed this?!".
I am in love with the books AND the TV show. I have my gripes about the show, but I knew the books could not possibly remain completely faithful to the huge novels, so I set my expectations at a realistic level. As long as they get the spirit and general storyline of the books correct, while keep it a fantastic show, I'll be happy. The only place I feel they've failed to do this is with Jon Snow, but I won't get into that here =p
As for the Jon Snow = Rhaegar Targaryen + Lyanna Stark theory. Yeah definitely. It's a pretty widely accepted theory. Less people believe it NOT to be the case, than believe in it to be sure =p
I'd love a thread to discuss crazy theories about the novels for people who have read them, there are so many things to discuss, but it'd certainly spell huge spoilers for TV goers.