I'm trying to find some papers on the web which would talk about significant improvements in Java with regards to improvements since 2002, but I cannot find anything. Could someone point me into right place, but please don't say go to sun website. I've been there and I really couldn't find any material which would discuss those improvements with relation to earlier versions.
The Java SE 6 performance white paper has a very detailed list of performance improvements that were introduced in Java 6, including benchmarks.
For Java 7, there is a much shorter document, which doesn't have any benchmarks.
If these aren't what you're looking for, you should describe your requirements better.
The wikipedia page Java version history has references to performance improvements and is a good starting point