Early days, yet, but I'd put my money on France!
They are unpredicatble, but can turn it on for the big occasion, especially with it being on home territory.
They are capable of playing very open, attacking, running rugby, keeping it in the forwards, or being able to muscle-up with the best/worst of them if it gets a bit 'physical'.
England? Q-F if they're lucky!
By the way- Kiwis will win; noone else has got any long term form at the moment. Ireland are great. but inconsistent. South Africans claim that they are 'playing their b team' sounds a bit hollow, especially in the short run up to this world cup (I know its 5 months but in rugby terms that's nothing). England haven't got a hope in hell, despite some positive signs in the 6 nations. France play great rugby, but not often enough. Kiwis have long term consistency on their side, but that means very little in practical terms - a mistake in the semis means that anything could happen. Odds are on the kiwis at the moment, but thee's still a while yet, a few key injuries can wipe anyone out (as us Brits know only too well).
Could be. Testing's been in place for years though (just like cycling ). Jamie Bloem was banned for two years a long time ago for the use of anabolic steroids. Don't forget they are big but not stupidly huge on the muscle mass front. They have access to good coaches and sports scientists and the top teams probably get nutrients for free. Their size is very doable to joe public if the time is put in and training is done properly.