I have a list of answers for this question but there's one answer that might surprise you: We miss a general-purpose-easy-to-learn-easy-to-use programming language.
I think this answer might come as surprise to most people while considering the abundance of programming languages around us like Perl, Python, Ruby, PHP and others but I always felt there was something else missing. Looking back at history I would like to take a controversial example for this topic from the commercial world: The VB6 example. Sure it was a horrible horrible language but people actually used it for their every-day use. I used to see it all around - Windows people wrote utilities with it, wrote prototypes and in some cases even entire projects with it (god forbid!). People were happy with it and that's what really matters.
In the distant past I loved PHP so much that I used to have this "silly" idea that PHP should be used everywhere - on server side , on client side (because I used to think JS sucks), for shell scripts and even for GUI applications but my colleagues and friends used to dismiss this idea by saying PHP is good for server side scripting because it was designed for it and that's where it should stay. I guess they were right but the idea that one scripting language can and should be able to do everything was stuck in my mind. I was a good PHP developer but I never really got to know JS as well (and that's too bad) but since than a lot has happened.
- node.js (js in server side, check out npm - the nice package manager)
- express (js framework to write server side applications)
- mongodb (schema-less database, JS-like syntax for queries and JSON for results, very cool)
- backbone.js (popular framework for client side)
- JQuery (who doesn't know this one?)
- Twitter Bootstrap (related to CSS but awesome for lazy developers who still like their poorly designed web pages to look good)
I don't know if it's the one language to rule them all (mostly because I was wrong so many times before :-P) but I can tell you one thing: The developers community is big enough, The projects are alive. Lots of ready-to-use components with permissive licenses, lots of support (in stack overflow). bottom line: lots of fun.