This one is 7.0! And only 7.0! I literally only changed the version number! Why am I shouting like this were a TF2 Update!
Anyway, 7.0 is out in patch form now, and we're working behind the scenes on installers and some other stuff you can probably guess at.
Update: 7.001 released to fix a bug with the fix to the scrapping-lightning-torpedoes-for-money exploit, and a few other things.
This is a standard update that you can download through the in-game updater itself, if you already have 4.000 or later. When you launch the game, you'll see the notice of the update having been found if you're connected to the Internet at the time. If you don't have 4.000 or later, you can download that here.