Pretty cool. Lots of features (including intellisense style completion, TextMate style tabbing through placeholders), sensible menus and shortcuts, integration with GAE and Django and VCS etc. Seemed to go through some slowdown at first but I think it's because I opened a project directory that was, well, my entire DropBox. My only complaint is the interface could be more Mac-like, but for a cross-platform effort it's decent. Impressed (could be a godsend actually, since the education licence is free, and I can't affort TextMate, and hate Eclipse).
Back in the day, I was a huge fan of IntelliJ (when I was still writing Java). I'm so tired of slow and buggy IDEs built on top of Eclipse (cough Zend cough) so I'm hoping that this makes my life easier.
I love intelliJ products.
I use RubyMine for ruby, phpStorm for php, and pyCharm for python.