Though I'd generally agree with your last statement (and relish in the amazement on one's face when I show them disassembled JVM bytecode for the first time), I

Though I'd generally agree with your last statement (and relish in the amazement on one's face when I show them disassembled JVM bytecode for the first time), I'd have to say that this is still quite a "special" feat whether you've written a virtual machine/compiler/interpreter before or not. I haven't had enough time with the source as of yet, but I'd wager to say that there is most likely a lot more going on than just caching already-cross-compiled classes or basic opcode mappings. Not to forget that this project looks to be quite literally implementing from the JVM spec (a la Apache Harmony).