Post by Ghostcrawler on the yet-to-be-announced changes for Paladins in Cataclysm:
We figured no matter who was last they were going to feel victimized. You shouldn't try and interpret too much by the order of the previews though. The fact is we're just not as far along on paladins as we are the other classes. We find it easier to work on a few classes at a time rather than say work on one class on Monday then a different class on Tuesday and keep rotating through them. We didn't pick paladin last because we hate them or because they need the most work or the least work or anything. It's pretty much totally random.
We haven't torn up the paladin talent trees in earnest yet, so the preview will likely be heavy on design intent and light on details. One of the changes we'll continue to emphasize with Retribution is trading more defenses for offense. A defensive dps spec just doesn't work really well in WoW.