IBM also had some very bright minds working on their J9 JVM which was aoriginally targeted at embedded environments but was so good it became their mainstream VM. I'm not sure how much "borrowing" it does from the Oracle VM, but it's definitely a different architecture.
Another language could do this of it had wealthy patrons with a keen interest to make it so. Google with Python might be a possibility, but they are huge Java users already and have some of the old Sun team working for them.
The JVM has improved performance by developing more advanced garbage collectors and profiling JIT compilers over the years to the point where it is the JVM is the fastest managed runtime out there. http://shootout.alioth.debian.org/u64q/benchmark.php?test=al...
Short version is that Java tends to take a lot of memory and a fair while to start up, but once it gets going it's very fast. A bit like comparing a Boeing to a small sports car. The sports car will drive you to the shop around the corner very fast. The Boeing will take a long time to prepare for takeoff, but once it gets going will leave the sports car behind in the dust.
Seems like Java community did quite a lot to get Java to perform better. How likely is it for a language like Python or Ruby to do something like that? I understand that these are vastly different technologies and we simply can't compare implementing a JVM feature in say a Python interpreter, but any commentary would be appreciated.