I had Mathematica 8 on a MacBook Pro running Mavericks. I just upgraded to Yosemite, and when I try to run Mma I'm told that I need to install the legacy Java SE 6. Apparently, I had recently upgraded Java to version 7 on that laptop and I'm not sure I had run Mathematica after that-- so it might be the Java after all. Java updates are motivated in part by security concerns, so going back to Java 6 doesn't seem like a good idea. Is there any hope of getting value out of the version 8?