I voted "infrenal", "Dark(?)" and essentials infernal hexblade.
I do not use warlocks in my game world, but the very concept of a "pact" with some greater power to "give" you power in exchange for...something...at some point...while being a very valid fantasy archetype (from Faust on down), seems to demand a "dark/evil" power/outlook of desperation.
The idea that entities willing to say, "oh, ok, here's some power in exchange for something" are NOT "evil" or after some ulterior motive just doesn't mesh with me/my sensibilities.
Naturally, this is coming from someone who uses and likes 9=point alignment in their games...so I don't expect things will develop that way in game to allow for "shiny happy warlocks holding pacts" heroic characters.
-SD