Value Types are coming in the next version of Java. Yes, it is great to be able to allocate on the stack, but then Java has better garbage collectors, including a completely pauseless one available commercially. Even in this announcement the new GC mentioned for Go is non generational. I have a feeling that even Java's good old CMS is better. Java also does escape analisys. All in all, once value classes are in, it is going to be awesome.
Go also lets you have fields in place in structs, like C and C++. In Java, all fields (except primitives) are references.