Well, first of all it's not her who pulls back a new "Alien." They can do it without her, she just won't return as Ripley. I've been on this site for the first time now and it seems like you care more for the "AvP" movies than for the "Alien" ones which I can understant, it's an AvP site.
Anyway, I consider "Alien vs. Predator" as a huge piece of sh*t. "Alien Resurrection" isn't great, but "AvP" is just cr*p (sorry). It's really a bad movie, if you can call it movie, Fox just tried to get a bit of $ by letting their "tentpole monsters" appear in one pic. I'd love to see a new "Alien" but if they do it I hope they do it right. If it turns out to be just an average monster popcorn flick, well, that'd suck. A new movie should have depth, great characters, suspense and a good story. They should go back to the roots ("Alien" by Ridley Scott) and make something similar to that.