Personally, I felt like the franchise was "liberated" from Ripley at the end of Alien3. I don't know which executive at FOX got it in their head that Weaver's character was necessary to carry the franchise and decided to put a clone of her in Alien: Resurrection. For the franchise, both Alien3 and A:R took the franchise nowhere because they were bound by an unnecessary character that nobody knew what to do with.
Even if Alien 5 turns out to be a huge blockbuster, I doubt Weaver will be in any Alien films after this one. Simply put, she's too old...so regardless of whether or not she dies (again) at the end of this film, her character will not be too long for the established universe.