I'm testing Snow Leopard for our IT team in preparation for it's actual launch. I'm currently running seed 10A394, which comes with Java JDK 1.6.
I found one Java desktop application that no longer runs under Snow Leopard, the app won't even start. The vendor is recommending that I downgrade to JDK 1.5.
The problem is that every Java for Mac package that I've been able to find first checks that it's about to be installed on the version of Mac OS that Apple had in mind when the package was created. This page is a good example, there are two different packages but each explicitly checks for MacOS 10.4 or 10.5 before installing, so neither works on Snow Leopard.
Once I get it installed, I know how to change the order so that the lower version is preferred -- I just can't find any packages that will install.