The steps for symlink'ing are totally necessary in order to get click through JDK source code in Eclipse. Of course, it could be argued that Eclipse needs to be fixed to automatically look in the new location, but that location changes for every update and isn't technically 'JAVA_HOME'.
The developer package you download from connect.apple.com is a full JDK in its own right, there's no need to link the sources to the JRE under /System. You just need to let Eclipse know that there's a new JDK in '/Library/Java/JavaVirtualMachines/' and make that the default in your Eclipse execution environment settings for 1.6; all your projects for that environment will pick up the new JDK along with the sources and docs. I link the specific JDK to 'latest' under the JavaVirtualMachines' and use that in Eclipse; that way I can just recreate the symlink after upgrading to a newer JDK and my IDE doesn't have to care.
It was previously included and is no longer included... It has been removed.
Well yes, but there's a big usability difference between:
"Finder used to know how to handle this file but now it doesn't. Please select the application to use for this type of file."
and
"This requires the Java runtime which isn't installed. Hit this button and we'll download it, install it, and then re-open this for you once it's working."
Not removed, stubbed in such a way it will be installed automatically when needed.
I Spotlighted for Java Preferences and when I started it I was told that Java will be downloaded. After Lion downloaded and installed Java the Java Preferences started.
IntelliJ et al works as expected.
You don't need to do these manual step the article suggests(for running Java apps). (See comment below when you need to do these steps)