We are Warlocks, if there are changes we will adapt.
I enjoyed stacking Spirit in Demo spec in Wrath. I enjoyed farming for Soul Shards.
I disliked the first iteration of Hand of Gul'dan for Demo in Cata, it felt too clunky in the rotation; Affliction's PvE rotation felt fantastic.
Demo is feeling sort of fun in MoP - I dislike the fact that there is only one spam-able spell in Meta for the majority of the time. Affliction feels a bit like something is missing from the rotation. With the removal of DoT snapshotting I am hoping that another mechanic will come along to make Affliction feel a bit better to me.
My point is that in nearly every major expansion or major patch the Warlock class has been changed in one major way or another. I have always adapted and found what was most fun for me at the time. I will always welcome change to the class if the design team thinks that it is the right thing to do, so long as the class always feels right to me.