Were all of those skills required for one job? Anyway, I sympathise with your situation.
There's a strong tendency for recruitment agencies to inflate the job spec with a lot of extra skills, because this allows them to use a check-list approach to filter out "unsuitable" candidates without having to think too hard. This is a real problem for applicants, because often the recruiter doesn't understand what the employer really wants, and doesn't understand how your skills/experience might actually be a good match either. Many recruiters are effectively marketing people - this week they're selling IT recruitement services, next week it could be double-glazing!
Another problem is demanding say 5 years' experience of technologies that didn't exist 5 years ago e.g. Flex, iPhone development etc. Again, this happens because the recruiters don't know anything about IT. Often employers let recruiters do this, then complain about the so-called "skills shortage", when really there is just a shortage of people with improbable combinations of unnecessary and irrelevant skills for a particular job.
In terms of which new skills to focus on, pick things that are widely used and will extend/complement your existing skills/experience e.g. try typing "GWT" or "Flex" into a job-search and see how many jobs come up, and what other skills are often combined with these. For example, Dojo (or Prototype)/AJAX/JavaScript are an obvious combination and there is a lot of interest in AJAX GUIs for web applications these days. These might make a good combination with your existing Java skills, because AJAX + Java (Spring/Hibernate) is likely to be quite a popular choice for many web applications these days.
Google Web Toolkit (GWT) is Java-specific and allows you to develop JavaScript AJAX GUIs using Java, so it's quite a good match with Java web applications, but is not as widely used (yet?) as conventional pure JavaScript tools such as Dojo or Prototype.
Adobe Flex is becoming very fashionable, but it's a proprietary tool (like Flash), so it may not be so widely used - you might be better off concentrating on more widely used free tools like Dojo, Prototype and GWT. Also, some of these GUI-oriented tools are used more by front-end web designers than back-end server developers, so you might want to think about whether you have the interest/aptitude to move into that kind of role.
As for other web technology, PHP is pretty easy to pick up (go for the free Zend Framework component library to give you lots of MVC and useful functionality similar to
Struts or Hibernate). Also you can try out free open-source PHP-based CMS tools like Drupal or Wordpress and look at the source code to get a feel for what it can do and how it works. These are easy to install on Apache/MySQL/PHP, and are well documented online.
But PHP is a rare combination with Java, unless people are developing a PHP web interface for a Java server application, and it doesn't seem to be used much for enterprise applications. Also PHP jobs do not generally pay as well as Java.
If you're looking at other scripting languages, Perl is of course widely used, while Python seems to be growing fast and would probably be easy for you to pick up as it's OO and there's lots of good learning material around on the web for Python, and lots of open source tools - frameworks, CMS etc.
If you're wanting to look at other web development tools, consider Ruby and Rails as an example of a powerful "convention over configuration" web development framework, or try Grails to get a feel for a similar approach built on top of the Java technology that you already know.
Look at other enterprise technologies that are widely used with Java e.g. how are your database skills with Oracle or SQL Server? As an unemployed Oracle developer, I can tell you there seem to be lots of Java+Oracle (or SQL Server) jobs around for people with the right combination of skills/experience. My impression is that an 80/20 mix of Java/database skills still seems to be pretty marketable. Unfortunately, I don't seem to have enough Java for these jobs right now!
You can get free versions of Oracle (Oracle XE) or SQL Server and there are lots of online tutorials and books to help you learn more about them - look at things like relational data modelling, SQL performance issues, packaged code for triggers/stored procedures (e.g. PL/SQL in Oracle), and specialised RDBMS tools e.g. for messaging, job queues, web interfaces etc. You don't need to become an expert in these things, but if you can talk about more than just the Hibernate API and basic SQL, it may give you an advantage over the next guy.
Sell your knowledge of enterprise architectural and design issues hard: there are lots of Java programmers, but not so many good system designers or architects.
Whatever development technologies you decide to look at, you could consider trying to build your own simple application on a cloud platform, just as a learning exercise. This is pretty cheap and will give you lots of popular "cloud-oriented" buzzwords to include on your resume.
Do you have any certifications? If not, why not get some, if only to give you a small edge over the 100s of applicants who might not have these?
Get advice from people who are (still) in jobs, find out what they're using or planning to use, and look at job-search websites to get a feel for the popular skillsets. Ask them (or even recruitment agencies) which skills they are having trouble finding on the marketplace. Maybe even offer to work for free for a while, if you know somebody who might be prepared to use you if it didn't cost them anything, simply to get some experience of new technology.
Also consider how you might learn more about a particular business/application area, or how to sell your existing business knowledge more successfully, because employers often complain that they can't get people with good business knowledge.
Finally, there's a good book called "The Career Programmer" by Chris Duncan (Apress), which has lots of sensible advice and observations on how to find/stay in work in IT.
Good luck!