For as little as I know on the subject - though some expect some authority from me, how horrible the idea! - this seems to confirm two opinions I have held for a long time:
-) Java and the kind of glittery web pages it allows are to be avoided where possible - and that includes the Java embedded in appservers like tom cat , web logic, and what not. Unfortunately, this kind of rubbish is hyper-attractive to the hyper-assertive marketeers that somehow seem to have gained (or been given?) control of today's world.
-) never be too hasty in upgrading one's PC - staying with 1.5 or 1.6 will run most applications, and keeps one on the safe side.