Sounds much better than I had hoped. Not bothered about the loss of Shaw, time will tell if this is actually due to Noomi not being interested.
I like the idea of David being alone on the planet, it opens up a level of ambiguity over what he says which will make everything more interesting.
Timeline wise I can't see this being after Alien - Remember in Aliens a 57 year cryosleep is considered really, really long. I can buy that this ship has set out maybe, 10 years before or something.
To the people talking about having a much bigger cast, I'm placing my bet now that it won't be a huge cast and they will just have the vast majority of the colonists in cryosleep, I can see a MUTHUR style wake up scenario for the crew of the ship to check out this "perfect" world - not the passengers.