Warrior talent · row 3 of Arms, from level 20 (15 with Talented 5/5) · Physical

Deep Wounds

Your critical strikes cause your opponent to Bleed, dealing 20/40/60% of your melee weapon's average damage over 12 sec.

Game files · build 1.60.1.70291Read straight from the WoW Forever beta client.

Compared with Classic

Classic tooltip

Your critical strikes cause the opponent to bleed, dealing 20% of your melee weapon's average damage over 12 sec.

What Blizzard said about Deep Wounds, each line checked against the files.

Matches the files
Deep Wounds is once again a required talent to reach Impale.
The files Build 70291 added a Deep Wounds to Impale link (trait edge 136737); Impale sits in Arms row 4 under Deep Wounds in row 3.
Deep Wounds Impale Development Notes, October 8
Not in the files
Fixed a bug where Deep Wounds was scaling with attack power for your Offhand weapon.
Developers' note: Deep Wounds does not scale with Attack Power but is a rolling DoT compared to Classic/Vanilla.
The files Deep Wounds (12834) didn't change in 70291; which weapon's attack power it uses is computed by the server.
Deep Wounds Deep Wounds Development Notes, October 8

69876 Sep 16First beta build we archived. No changes in the client files since.