It would be a shame to lose desecration.

Although the new Desecrated Ground ability will be in MoP for DK, desecration was a bit more than that.

I remember picking up desecration while leveling my DK in the first few days of WotLK and having it with me throughout the whole expansion (minus those few weeks I was Frost in Ulduar... oh the power).

It was part of the class to me, or at least the "Unholy" aspect. Wherever I was going, so would desecration. To me, it was class refining, even in the situations where it wasn't doing much of anything.

I don't know if I'll be playing my DK in MoP. Probably I'll go monk, but don't take this ability away from Death Knights. It is innovative, flavorful, and fun. The fact that the new talent system would make it possible for EVERY DK to have this ability in their spec is great, but it could be weaved into the Unholy DK path as well.

I sure that the loss of this ability would be a mistake.
I'm sure they just havent added it to the list. What I like is contagion is unholy baseline. Not that I hardly ever use pestilence but if the diseases were buffed a bit I might use it more.
Let's hope so.