Well, there's this:
Quote:
Degeneration (Rank 3, Level 76) - Instantly attack the target, dealing 60% weapon damage and inflicting a disease dealing ${$m2*7} over 15 sec. This disease will corrupt an existing heal over time spell, removing it and dramatically increasing the damage dealt. While afflicted by this disease, other heal over time effects on the target will have no effect.
Which has obvious druid crushing application 0_o but also count as one more disease from a PVE point of view.
Degeneration + Plague Strike + Blood Strike (Or heart strike) until disease fall off seems like a start.
Some Talent (like Crypt Fever) can also go from 'meh' to 'holy **** that's broken!' depending on how many disease are actually available. A 6% Attribute lost PER disease get pretty bad *** if the DK can put 3 (And he should be, Plague Strike, Degeneration and Unholy Blight are all disease ability we know about and their description make them sound like 3 different debuff) or more disease on a target...
That's a lot of dps lost and a sizable chunk of HP as well.
The talent says it also applies to the disease from the Ghouls... Imagine if DK and Ghoul's disease are 'different', allowing for 4-5 difference disease on a target...