Description
When plotting with the OS X backend (%pylab osx), the IPython qtconsole1 will hang while a plot window exists. This is indicative of a failure to actually enter interactive mode.
A trip through git bisect suggests that the bug was introduced in 2f11dee, ostensibly purely style changes. I didn't see anything obvious, but I cannot reproduce the issue with 76bba3d, and I can 100% of the time with 2f11dee and current master (17e1cf8).
The OS X backend works fine in terminal IPython (where inputhook events still fire), and the Qt backend works fine in the qtconsole.
This is OS X 10.8.2, with System Python 2.7.2, IPython master, etc.
1 qtconsole is not actually relevant, any IPython kernel-based app, such as ipython console or the notebook is affected.