I just like bigger numbers.
Also, most of the computers I setup aren't touched by a technician for many years after they are first configured. It doesn't matter if nothing uses Java 7 now. In two or three years, it might be another story. I'm not sure the Java update will update the platform from Java 6 to Java 7, but I'm pretty sure that if I install Java 7 right now, it will complain about installing updates for the seventh version later on, so there's an odd chance my customers will have a recent version of Java in the upcoming years. Otherwise, only those who will have screwed their systems and will call me to fix it will have an up-to-date Java engine.