He began by building the engine, and to do this he used 
    the ‘HotSwap’ functionality of the Java JVM 1.4.2, which 
    continuously updates the running code when it detects 
    that a class has changed.

    If anybody at Google is reading this, if you add this 
    feature to the Android emulator and I will literally 
    drive to your house and kiss you on the mouth.

Indeed, the fact that Android doesn't already have this makes it hard for me to take it seriously as a platform. Immediate feedback is crucial to any development environment.