Steve Yegge has made a good write-up on languages: http://steve.yegge.googlepages.com/tour-de-babel. Steve is a top notch programmer with brains and eloquence. He was one of the first hackers at Amazon. Now he works at Google, and Google has chosen Python and JavaScript as company languages. Which has pissed off Steve quite a bit, because he has firmly decided that Ruby is more powerful and rewarding than Python. But he's not allowed to program in Ruby at work.
So, Steve has engineered a kind of 'JavaScript on Rails' in order to fit into Google. All to avoid programming in Python. JavaScript is more powerful and elegant than Python, as he sees it.
This gives you two clues. One about Ruby and second about the Rails. To be brutally honest, Lisp is the most powerful and beautiful language to approach a programming problem. But List is not the most practical choice because of lack of libraries and dialect balkanisation. Ruby is considered to be an 'acceptable Lisp'. Almost as powerful and much more practical. And very very elegant. You may hear a lot about Ruby being slow. That is true, but that is also changing fast. Make your own research. You'll hear some interesting thoughts about what 'programmers' time' is worth vs. 'processor time' etc.
Finally, the frameworks. Rails has been mercilessly hyped, but the fact remains -- it is a framework for programmers. It has digested lots of 'theorizing' from Java and Smalltalk space. It tried to answer the question: "What an ideal MVC framework would be?" The answer turned out to be surprisingly good.
Django is a clever framework, but it has arisen from a particular website (Lawrence Journal-World) and it still has roots in website page design. Nothing wrong with that, but programmers talk less about Django (just check IBM tech articles), there is less programming 'meat' in there. There are also much lesser number of plugins and hacks for Django. You do not have the same amount of books and general enthusiasm about Django platform, comparing to Rails. Not by any objective measure.
Now let Python fanboys kill me, but I went through the same analysis a couple of years ago and I came firmly in favour of Ruby and later in favour of Rails. And I have not been disappointed a bit ever since.