Nerf Now!! 1590
If you are looking for the big winner of this patch, don't look too much, Heavy got it.
To start, as one of the few classes to receive no nerf, he already jump ahead of the patch. One of his strongest counter, Loch and Load demoman with good aim, just got hit hard, and while the weapon is still viable versus Heavies, I don't expect it to be used as much now it doesn't do extra damage.
But the juiciest part is Brass Beast and Natasha 20% «armor». While Brass Beast is still unusable as ever, you are basically trading 20% damage on Natasha for extra 20% HP, sounds pretty fair, until you notice this 20% turn into far more when a medic overheal you. A full healed Heavy now have essentially 540 HP if he is full overhealed and spinning. Good luck killing him.
And as a bonus, he don't die to a full charged headshot anymore, a very common event if you were pushing the cart with your minigun down.
Now, more than ever, killing the Medic is priority one to any team, otherwise I can see a single Heavy+Medic combo mow down the whole enemy team.