Well on a different matter: Some here say tv-series are better than movies but most tv-series Ive seen have had watered down conceopts and quality of what a movie would bring in, better quality in screen/cameras and effects while tv-series always thinks about budgets more strict and saves in on effects and most episodes are just fillers which to me is tiresome.
Looking at terminator sarah connor chronicles, games of thrones, robocop, firefly/serenity, etc.
Also alien is horror and no tv series I have watched has ever done good horror, drama maybe but so slowpace that one wont be afraid or jump or start nervously talk due to how scary it is, I doubt a tvseries can reach the horror level of the thing, alien/s, evil dead 1, the descent etc.
I dont see a tv series managing doing that episode after episode of nail birting gore and horrors that alien fans want.