Run a diff against the codebase (not that I have or would or will) and then you can see what work has been done. Often releases of codebases with any software is not something with big gains readily visible to a user or event a software engineer. Sometimes its alterations or additions in code for any number of reasons, security increases, codebases that need be vamped out in production environments that are to be supporting code for future application infrastructure or any number of other reasons.

I am sure with a product as mature as WP they dont just go, "Geee... lets make a primary release because we need make things look like we are"... Not at all, I am certain of it.

But like I said, run a diff against the codebase and you will see it. Simple.