PHP doesn't require any libraries to build a simple website. I've yet to see any document that shows in great detail (more than a simple 1 chapter static page based site) how to build a website using Ruby or Python by itself. No libraries, frameworks (no Rails, no Django) or other external stuff, just plain old Ruby or Python. I think this combined with the fact it's very easy to learn, the ton of tools out there, ton of web apps make it a hard language to kill.
What really can be done? Should they make a new version that provides more consistant function names and break backwards incompatibility? I've yet to hear what people think should be done with PHP besides abandoning it.
That being said I don't think it should die, I think it has it's place. I'm not as smart as the rest of the folks on here, but for doing client sites, PHP gets the job done very fast.