I've personally seen a scripting language been thrown out and everything rewritten in Java.
After a couple of years they had to go back to scripting languages for a big part, for productivity. So they would ship sometime... (To minimize embarrassment, they used a different scripting language. [Edit: Yes, the second scripting language have almost as much hype as Java...])
<offtopic> It's been a while since I worked with PHP, but when looking at performance or distributing work I can appreciate the desire to migrate to a different language. I've always seen PHP as more of an over-ambitious template language (even though smarty and so on exist to perform this function on top of PHP). Basically I'm not surprised by your story. </offtopic>
We don't like Java, but the JVM has met our needs pretty well. I was tempted to argue for Clojure, but I'm not sure we could have taken the performance or maintainability hits for discouraging static typing.
(I'm right now relearning css, javascript, dom etc. The present place is getting to be a bit non-challenging and boring. And I promised myself I'd work hard to do interesting things the rest of my life.)
Edit: I might add my 2c. I have no problem with Java, really. It is like a simplified C++. It is just boring.
I've been in the situation several times where technology decisions are made based on brand. The Java solution is the only one evaluated "just because".