This is a lot more likely than a quad-core processor. Apple isn't about checking boxes off a spec list. They put in the features and specs that are necessary to deliver the features they want, not to keep spec-hungry tech fans happy.
How many people even know what a quad-core processor would add? On the other hand, Apple can tangibly demonstrate the benefits of haptic feedback. Haptic itself isn't anything new (my old Nexus One has some haptic feedback), but Apple usually delays introducing something until they can do it right. Haptic may well be at that stage now.
On a related note, while the iPad 3 may also have 1GB of RAM, we won't know for sure until iFixit or someone else tears one apart to look. Apple isn't likely to say today.