After a rather long lapse, I had the occasion to write some Java code recently (mainly because it didn't look like Howard's PySDE was functional).
I didn't like it.
Not to start a language flame war, but after using Python almost exclusively for 6 months, I found Java to be cumbersome. I kept thinking "if it were Python I could do it this way".
Sending an email from Java--frightening. From Python--simple.
Lest you think I'm a Java newbie, I've been using it for both desktop and web applications for over 10 years.
Its ease of use and rapid development time, coupled with the fact that Python is the de facto "GIS" scripting language in most arenas, makes it my new favorite language.
Of course the old axiom still stands--To each his own...