Rodney talks racial ability score penalties (specifically, the lack thereof), unarmored clerics, and the creative and balancing process behind monsters.
Ability Score Penalties
I was really happy that 4th Edition did away with pointless racial penalties, which resulted in a lot of interesting and--perhaps more importantly--effective race and class combinations. I always cite the halfling fighter as a prime example of something that just did not work in 3rd Edition due to both her penalty to Strength, and a hefty collection of other penalties based on size; smaller weapons, a penalty to Speed (made worse when compounded with heavier armor), and a penalty to lots of checks that tended to come up when fighting brutish monsters like ogres and dragons.
4th Edition made it possible to have a readily effective and thematic halfling fighter without any optimization involved, because while you did not get a bonus to Strength, you did not get a penalty (though you did get a bonus to Dexterity, which made you better off with light and heavy blades). This change predictably did not result in a slew of halfling fighters (or dwarf bards, half-orc wizards, elf barbarians, etc). What Rodney says makes sense; races with the right bonuses and features are more likely to get picked for certain classes, so why bother penalizing a race so that it is bad at others?
In other words, just because a halfling makes a competent--and, depending on how you make it, thematic--fighter does not mean that it becomes my default choice, or even one of my top five or whatever. There are still humans, dwarves, goliaths, half-orcs, warforged, minotaurs, and more that have modifiers and features way better suited for the job.
The "White Mage" Cleric
I was one of the people disappointed by all the universal armor and weapon proficiencies, and am all for a clerics god playing a greater role in what she can do; war clerics should (probably?) be better at fighting than clerics who worship gods of healing, trickery, and love. Turn Undead also needs to go. I cannot see a god of trickery giving two coppers about what happens to undead critters.
The current process basically sounds like what I always assumed they did, at least in 4th Edition: try to give monsters a noteworthy shtick to help differentiate them from the rest. In 3rd Edition fighting goblins was basically the same as kobolds. There were both Small-sized and either threw things at you or tried to stab you. That was basically it.
In 4th Edition goblins could scramble out of the way when you missed them, and kobolds could easily scamper about. It might not sound like much, but what it translated into was goblins breaking out of tight spots when it was not even their turn, while kobolds could easily get flanking and escape.
Speaking of 4th Edition, I greatly preferred its stat blocks. Easy to navigate, and I never needed to reference another book in order to make it work. I also liked that a lot of similar monsters had powers with synergy. Made them a lot of fun to play.
Internal stress-tests are always good. Hopefully they are looking into shambles of zombies taking forever to kill by low-level characters.