Hey, an actual interesting L&L article! Shock and amazement!
Druid - I like the idea for Wildshape, but I'm expecting "Shape Bloat" to be an eventual problem for the Druid. Personally, I'd prefer some sort of modular system; you get base stats plus some adjustments for each form. That way, for example, you can model a bunch of Medium Animals (dogs, wolves, what have you) and have them be relatively balanced. In this system, you might choose classes of forms instead of specifics (ex: Medium Animal, Tiny Animal, Medium Elemental, etc). I guess it ends up being a sort of 3E/4E amalgamation.
Ranger - The problem with the Ranger as a class ties back to the problem with the Warlord from last week's Q&A. That is, while the concept holds its own weight, the class itself is designed as basically a "Fighter-hybrid." In this case, taking away the Ranger's TWF/Archery (a good thing, IMO) leaves the Ranger with Favored Enemies and... well, that's it really. The Ranger's "wilderness lore" has most been covered by spells since the days of AD&D. So it makes sense to fill it with spells (presumably with overlap from the Druid).
Paladin - I like that the Paladin has taken over the "knight" archetype from the Fighter, and that the class is designed to be easily extensible. While the default options are based on good and evil, it's certainly possible to extend that to be alignment-neutral. I also like the continued separation of the Paladin from the Cleric in the realm of power source. I suppose that you could make Oaths or re-skin them to be based on Gods, but this way there's no built-in obligation.
Fighter - I'll have to see the mechanic in action, but I like the flavor evoked by the idea of pausing in combat. It follows the flow of most combats a little more realistically, in that there's a series of attacks, ripostes, defenses, trades, and then a slight pause before the next series. I like that damage bonus is gone, but I'm extremely skeptical of multiple attacks; that was a very onerous issue in high-level 3E play. That said, I very much like the implication that while all this new stuff is being developed, they are still iterating the older stuff as well. Obviously the Fighter is getting another pass this time around; hopefully the other classes get additional passes as well.