Don't know about how much more PS3 content there will be, but the 360 is supposedly going to have between 100-200 new titles (I'm sure most of these will not be AAA, since that would be bad for business). Considering what happened with ACM, i'm assuming Isolation will be on the newest generation, because it's a chance to separate itself from ACM. Due to the failure with ACM in technical aspects (Shadows, textures, ect), I'd imagine CA would want to nail this one down right, Fox or Sega will be looking over their shoulders so they won't take the kind of loses they did over ACM.
So I'm not concerned about the technical stuff, Alien being a big franchise I doubt they'll allow two terrible games in a row. I'm more concerned about the story aspect. It's called Alien, but we're being told there's more Clones and Soldiers to fight than actual aliens present in the game. I think this is a huge part of ACM's downfall, humans were everywhere.
Also still freaking about the FPS part of it. Like I said before, I've never played or have seen an FPS than was actually scary. I was hoping for more of a tomb raider, 3rd person kind of thing. Not just because the aesthetics were good, but the brutality that the protagonist went through was demonstrated on character (injuries, bandages, torn clothes) , and I've kind of hoped since that Alien would lean in that direction. I read somewhere that this was going to be puzzle centric, made me think about the early resident evil series, and that sounds great to me.