That's the story that gets told, but how often have they actually removed something after deprecating it? Does anybody have a single concrete example of a method that actually went away?

http://stackoverflow.com/questions/18063599/has-ever-anythin...

I don't believe they have ever removed a Class or method from the JDK... Thread still has all of those super-unsafe or non-implemented methods in it (see: stop(), destroy() etc.)

I think part of the reason for this ultra-conservative approach might be that alternate JVM implementations could in theory have well-implemented versions of deprecated methods such as the above-mentioned Thread ones.

No, they (Sun) could not care less for alternate JVM implementations. The reason for that ultra-conservative approach was that they were hell bent on keeping compatibility.

System.getenv was deprecated (in 1.1?), and then replaced with an implementation that threw UnsupportedOperationException (in 1.2?) because it was considered to be non-portable.

Later they saw sense and re-implemented it and un-deprecated it.