It has been quite some time that people have been coming out with statements of Java's demise. But to see Elliotte Rusty Harold in his post Java is Dead! Long Live Python! do it caused me consternation to no end. You may want to check out his web page to get a sense of his contributions. He has written at least four books on Java including those related to XML Processing, IO, network programming. Incidentally he has also written a book on Beautiful Code (more on that later). I would suggest you read the post first, if the remainder of this post is to make any sense.
I must confess that after having spent years in Java, I like Python more. But I like Python more because of the nature of language that it is. It is natural in its flow (I like the mandatory indentations), its ultra slick programming constructs (ruby actually is a tad slicker but I dont find myself comfortable with its syntax / style and the special characters in the variable names), and its ability to really get a lot of work done with very little code. But having said that, I have no reason to believe or assume that Java is getting threatened in any particularly significant manner from these upstarts such as PHP, Python and Ruby. They are collectively not strong enough as java and are unlikely to pose a threat to Java in the market the matters the most (at least yet) - corporate enterprise software development. Corporates need comfort, and they need comfort that stems from a strong support and promise that they can count on. And they especially need that for enterprise (non workgroup / non department level) applications, and enterprise level application development hires most of the programmers (I can almost hear others starting to yell - buts its true).
I don't intend to suggest that the newer languages cannot take on the challenges of enterprise software development. But choice of language and platforms in this context is a rather complex process - a process that involves far more than syntax and aesthetics of coding. Backward compatibility is a big deal. A very big deal in this world. You can (and I do) blame Microsoft for all its sloppy software and bloated code base but the fact remains - they made sure that they maintained backward compatibility. In fact, I believe maintaining backward compatibility and compatibility across a large number of devices is what definitely bleeds Microsoft of a lot of time and attention that they could have spent elsewhere.
So we find the academics sitting on large campuses, joined by many people in the web 2.0 / cloud computing environment and some from the workgroup / department application development space, getting gung ho about the newer languages and their cuter syntax, the brevity and the sheer power of productivity (I am one of them). But what they miss is that java solves important plumbing problems. They will realise it even more if they had attempted to deal with distributed cross platform computing in the years of yore with tools such as RPC / DCE / Encina / the various CORBA servers and services etc. etc, and deliver on the same across a whole range of platforms. Through 1996 - 2005 I believe Java solved the problem of platform independence, distribution and binary portability. And that too in an extremely impressive and credible way. You have to realise that the strength of Java is its inclusivity. It attempts to work with everyone and everybody who may want to work with it. Including those who long since adopted it in its early versions and continue to use those versions today. While many language communities attempt to crowd the etherspace with pro-my-language messages, java stands out in the fact that it doesn't attract deliberately but it does not turn anybody away. Ever.
Sure Python 3.0 made some very welcome changes, and sure many of the changes make the code become much more intutive, but make no mistake if java generics had broken backward compatibility, its economic impact would've been far in excess of that triggered by all the version upgrades of Python, Ruby and PHP put together. I do believe that this approach will eventually lead to substantial subobtimisation but thats still some time away. Moreover Java needs new features and enhancements like Yul Bryner required a hair cut. Java already has so many features and capabilities, new features wont matter much in the overall scheme of things for quite some time. Java is fine, it doesn't particularly need to grow.
Whenever I write a new application for myself, Python shall always have the first right of refusal (ie if Python doesn't meet the requirements adequately, only then will I evaluate other languages). However when required to build an application for a customer, who wants the comfort that his application will continue to run for another 10 years at least without him having to make any changes or enhancements to the code and be able to move it around from hardware to hardware, you exactly know which language I shall choose - Java. Thats why despite all the assertions of java being threatened, and even as other languages continue to grow thanks in no small part due to the additional developer productivity promise, I think java shall remain undead for a long long time (all the versions continue to coexist). For java we shall have to say something of the sort - Java 6 is undead, Long live java 7. And 10 years from now just like today, no one is likely to lose his job for having chosen Java. Thats why I strongly believe Eliotte was so wrong.