Well... spin up would improve, sure, but the much bigger issue is that a system quickly becomes bloated by code, cloned for a significant number of java process

Well... spin up would improve, sure, but the much bigger issue is that a system quickly becomes bloated by code, cloned for a significant number of java processes. And the number of processes will only be increasing because of multiplying CPU cores. I think the biggest innovation in systems programming would be to merge a VM with Linux kernel, i.e. the kernel should have a garbage collector and byte code compiler built-in. This would bring tremendous performance gains and programmer's productivity improvements. Microsoft is slowly moving towards that direction: .NET is already tightly integrated into the OS: at least all standard .NET libraries are pre-compiled, and shared across processes: using C or C++ on Windows makes absolutely no sense right now. By introducing GC into Obj-C Apple is doing the same thing. Next step for them would be to bring in LLVM and suddenly JVM on OSX will look even weirder than it does now.