Overall I'm pretty pleased with what I read in this article. I look forward to the new packet!
Druid: I'm glad that they're giving wild shape at level 1. I'm also glad that they're getting specific forms instead of being told to look through the monster manual and recalculate your entire character. That said, a hound? Huh? Wouldn't a wolf be more thematically appropriate? It's a minor nitpick, I know.
Paladin: I'm not fond of the alignment-division, but at least they don't have to be LG, so it's a HUGE step in the right direction, and I can live with this. I'm also glad that good paladins can only detect undead and fiends, instead of having a plot-breaking evil-radar. I'm not sure how I feel about the warden being a N paladin. I'll just have to see it.
Ranger: I love that favored enemy gives benefits that are broadly useful, so you no longer have to hope that a specific creature type will be in the adventure. I'm not fond of the spellcasting, however. I think spells should be optional. I also am not happy that TWF and Archery are being removed from the class. I hope this doesn't mean that my ranger can never use things like Rapid Shot without multiclassing as a Fighter! I think it would be better if they let you choose between a fighting style and spells.
Fighter: It looks like expertise dice are once again a fighter-only thing, so fighters finally have something unique to call their own. I'm also glad that they're a sort of encounter resource, rather than something you use every single turn. That gives it a nice strategic element that was lacking before.
Math: Thank the gods, MDD are going away! I'm a bit leery of extra attacks, but as long as they keep them in check (say, no more than 3 attacks by level 20) and don't have any kind of confusing iterative attack and full attack action nonsense, it could work.
Plus, since martial character attacks won't scale in damage anymore, cantrips no longer need to become better than 1st, 2nd or even 3rd level spells anymore, restoring spells to common sense. Hopefully, this will result in alot less people complaining about at-will cantrips.