Thousands of Fortune 500 companies?
Name one that uses Java on the Mac to implement central, mission critical services.
Hell, I'd be surprised if any of them that are committed to using Java have rolled Java 6 into production yet, given SOX.
That's true, most large corporations are still using 1.2, 1.3 and in some cases 1.4 (just look at how Struts 1.x, which is 7 years old still has a 60%-70% market share). However, there a lot of developers such as myself that are involved in small, pet or open source projects that require 1.5 and can take advantage of 1.6 when available, or that like to stay up to date on the latest enhancements to the language and want to work with it on our Macs.