As Java 5 reaches End Of Service Life (EOSL) today, does that mean that you'll be upgrading to Java 6 today, if you haven't already? If you want to have support for Java 5 further than today, you'll need to switch to Java SE Support for Business.
I moved to Java 6 as soon as it became available, but I was able to do this as the product I was working on hadn't yet had it's first release. I had no bad experiences in the transition from Java 5 to Java 6. In fact, because of it's better performance, I got a lot of benefits for free.
I'm interested to see if people are still using Java 5 and why.