Is Java "dead in the water"
Absolutely not. Far too many companies and people have invested in building Java software for Java to be dead in the water.
What exactly, or even approximately, are the legal ramifications?
On the face of it, there are two significant things alleged by Oracle's lawsuit:
The copyright violations are difficult to get a handle on, because it is not clear what Oracle is alleging has been copied.
The patent violations are more tangible, but it is unclear if the patents would stand a challenge based on prior art, inventiveness, etc, or whether the SCOTUS ruling in Bilski undermines them.
The legal outcome is unclear at this stage, and the consequences are unpredictable. Maybe Google and Oracle will settle the lawsuit, some money will change hands, patents will be cross-licensed, and we're back to business as usual. Or maybe it will go to court ...
I thought Java was open source and would therefore remain unaffected ... ?
All Sun Java sources that have been released under GPL will remain open sourced. Java 6 and 7 cannot be un-GPL'ed. Hypothetically, Oracle could change their mind about future releases, but I predict that it won't happen. A couple of days ago Oracle announced they remained committed to Java being open source, and that they were going to open source JavaFX. An about-face for Oracle on this issue now would be a publicity nightmare.
(Incidentally, the Google / Oracle spat is about Java on mobile devices; i.e. JavaME. The JavaME codebase has NOT been open sourced.)
Should Google just buy Oracle to get rid of the whole mess, that would be cool wouldn't it ?
Could they? Probably not. Oracle is probably too big for Google to buy.
Should they? Probably not. But that would be a business decision, not a decision based on "coolness" ... or doing the Java community a favour.
Would it actually be a favour for the Java community? I'm not sure. I'm not convinced that Java would survive the rampant moving-target-ism that seems to be rife in the Android world under Google's stewardship. However, this may just be "a teenage phase" that Android is going through.
Do you think this is the beginning of the end for Java as a widely used language ? Its continued success as an open source/free technology is now doubtful?
Unclear. Probably not. Java still has lots to offer, and the Google / Oracle debate (and even Java's open source-ness) is not relevant to most developers and businesses that use Java.
I'm inclined to the view that it is Oracle's ongoing level of investment in Java that will determine Java's long term future. And their ability to hang onto key Java engineers ... given the change in corporate culture. If Oracle fumble this, there is a chance that Java will fragment, and that the long-term future will be in some non-Oracle dialect of Java. (Maybe something coming out of Google or maybe something else.)