Warlocks in Cataclysm
Sorry, we just don't agree that that is a problem. It doesn't really matter if the talents are in a tree with a different name than your spec as along as the talents are useful, and those 15 certainly are.
To reiterate, we like Affliction using Shadow Bolt. We don't want Affliction to rely so much on Drain Soul because that feels a lot like a Shadow priest, and we don't like any class casting nothing but dots. So Shadow Bolt is sticking around. We also don't have a problem with Shadow Bolt being a Destruction spell and being buffed by the Destruction tree. Furthermore, we have no problem with Destro using something other than Shadow Bolt even though it's a Destruction spell. Finally, we don't mind that all of those talent points buff one spell. It's a really important spell! If you had to spend 15 points to buff a spell that was a trivial amount of your damage it would be a bigger deal, but then I'm fairly sure nobody would make that talent point investment in the first place.
All of those arguments seem like they offend your logic or something, which isn't enough grounds for us to want to change it. Different classes work differently. Mages focus on a school of magic while warlocks focus more on a source of damage (dots, pets and nukes) but even in that case, that doesn't mean they focus on their damage source to an extent that the mage focuses on Fire, Frost or Arcane (and in Cataclysm all mages will care a lot about Arcane Missiles in any event). We are really trying to resist class homogenization and having talent trees constructed similarly for every class works against that goal. Not similar is fine. Not functional is not fine.
What does bother us is having to get both Affliction and Destruction versions of hit, threat reduction, pushback resistance and range in addition to the crit damage from Ruin. Our plan is to put generic (affects all spells) talents for hit and pushback resistance in the first tier of Demonology and then just make the spells longer range so there is no need for a range talent. We're getting rid of all threat reduction talents. With the extra Cataclysm talent points, you should have more than enough points to get some in Demo and Destro as Affliction, and in fact we're leaning towards warlocks being one of those classes that does invest a little in all three trees. (Though again, not to the extent that you have no flexibility.)
If you're one of those warlocks who just really, really wants Affliction or Shadow Bolt to work differently, well, you have my apologies. No doubt if you were in our shoes you might design different talent trees. I have tried to explain our choice for the design above.