This seems more easily parsed by humans. My immediate faction to this is a positive one. Instead of having to scan the entire class to tell whether or not a variable is static, it's declared in the method itself.

I don think it is very useful or practical. A similar effect can be done using static variables declared outside the methods.

But it is a good example on how to write a plugin, with annotations and instrumentation. So the interesting parts are on the code implementing this functionality.

I'm a little unclear on its purpose myself.

Also, it seems like (if abused) it would make unit testing really cumbersome without some sort of side-effecting mechanism to expose these persistent variables.