I'm thinking it will be a mash up of art styles. I'm guessing the aesthetic the art department has embraced will take some of 'Prometheus' lavish looking sets and dressed it with some of the retro-future presentation of 'ALIEN'. Throw some empty beer cans around the place, drape it all in failing neon, add puddles and have some hare krishnas wonder through the set. lol.
'Blade Runner' did have some remarkable production design, that's for sure. Revisiting that philosophy in an 'ALIEN' movie would be fantastic!