Hehe

Then you forgot everyone still on 1.4.2 (there are a lot) or worse, on M$ JRE 1.1
Blame on M$! Stone them! Hunt them down!... Well, We don't have to and won't care about anybody using 1.1. And I guess, it is a half-compatible M$-Java-implementation, which is anyways meaningless.
If you want progress in an API and want to improve it, you sometimes need to abandon support for older versions. And I think, Sun should abandon the "direct" support for JREs older than 1.4 and once older than 1.5.
Myeah, but users want support, too. About the M$ implementation, you're kinda generous with M$s when you say "half-compatible"

maybe "quart-compatible" is even too much.