So there is EXACTLY ONE version of Java that is usable: 7u3. There is NO PATCHED version of jre6 or jdk6 that is available for our 80,000+ workstations managed by Tivoli that have jre6 installed. Upgrading to 7 requires going through Field Certification of months of application compatibility checking.
Not to mention the servers that have jdk6 installed to a specific path, jdk7 would go in a different path and require changes to configuration files and regression testing. This is a 2-3 month process usually rolled into other development processes and doesn't just drop on the datacenter in one day. I think at least five departments would be involved in getting this change implemented.
No, Mozilla should be forcing this on Oracle to release a patched and updated 6u31 that can be automatically pushed to all machines, then wait two weeks and drop the hammer on anyone left behind.