Wouldn't be surprised if the Oracle issue is involved: they are after all also not bundling Java (which is required on first boot (rumor?) but by lots of software in any case). I can imagine they don't want to mess with possible lawsuits or licensing fees in the future with the path Oracle is on.
I installed Lion a few days ago, and Java is not installed. The first time I typed java (or javac) on the command line, it asked if I wanted it installed - it was then automatic, I just had to wait a few mintes.
