I just received an email from my local cinema chain here in Sydney (of which I used to be a member) promoting a competition to win tickets to see "The Hobbit Trilogy Extended Edition".
Putting aside that such an experience is probably also something they do to detainees in Guantanamo Bay, it just made me think that what would be most interesting would be if someone would host a live reading of the book at the same time and to see if a complete cover to cover reading of the book would be finished before it was possible to watch all three extended editions back to back.
I'd say there'd be fairly even odds.
A quick calculation suggests that all three extended editions back to back would be about 8 hours and 50 minutes, while Rob Inglis' reading is 11 hours 8 minutes. So maybe a speedy read.
This site, however, suggests that a silent reading of the book is definitely faster than watching the non-extended editions, although this was approximating the length of the third film.