Bishmon said:
Well, good clerics and paladins deal more with good deities, the same way evil clerics and paladins deal with evil deities. Evil warlocks deal with evil outsiders the same way that good warlocks deal with good...oh...wait...
That sounds like a GRE question: "Good clerics are to good deities as evil clerics are to evil deities. Evil warlocks are to evil outsiders as good warlocks are to __________."
I don't see why we need absolute coverage in potential power sources for warlocks in the PHB. I've already suggested that they could add in a "construction kit" not unlike those found in Arcana Evolved for witches and champions, to build your own warlock. I've also suggested a long list of potential warlock power sources in one of the original "oh noes, warlocks are forced to be evil" threads. If you're dead set on playing a character who gains power from a pact with a good outsider, play a cleric and wait for the inevitable supplement detailing good warlock power sources. Or, and this is the tricky one, just say that you serve a good power and that your powers all have special effects that include nimbuses of light and angelic choirs rather than hellfire and spooky.
When it boils down to it, the differences between the various warlocks are likely to be purely mechanical, if there are any differences at all. We might see three different power lists, or just one list. In any case, any warlock list is a set of mechanical effects with flavour attached. It might be a pain in the butt to strip out the flavour of an infernal set of powers and replace them with celestial flavour, but I don't suppose there's any way they can stop you from doing so. Instead of discorporating into bats, you turn into butterflies, or babies with wings, or flying sugar-free chocolate, etc.
The bottom line here is that the warlock is
supposed to be the class with creepy dark arcane powers. It was part of the draw of the class when it appeared in Complete Arcane (and they eventually released a celestial version in Complete Mage, so I don't expect they'll leave you completely out in the cold). Sure, you could build one that doesn't have them, but there's no reason to clog the book with optional builds designed to appease messageboard contrarians. Leave that for the supplements, since a flavour text change is all that's required to turn the class into sunshine and rainbows.