Linux 3.0 refers to the kernel, not the OS. It doesn't break any significant conventions, so from a user's perspective it just works as they have come to expect.

From the coder's perspective, things are cleaner, and there's a bit of new to learn, but it's not a complete revolution. not a big deal here either.

The 3.0 moniker is a mark of the code maturity and revision, nothing more.