Here's what I've found thus far.
PHB3 adds the keywords: Psionic, Augmentable, Full Discipline, Runic, Varies, and Zone (the latter two have probably occurred elsewhere and I just haven't come across them because I haven't played a character using powers with those keywords). Most of the Monk powers with the Full Discipline keyword have an Attack Technique and a Movement Technique, which fill the Effect slot in other powers. The Psionic powers with the Augmentable keyword have Augment 1, Augment 2, Augment 4, or Augment 6 listed, again filling the Effect slot of other powers.
Skill Powers are added, which are Utility Powers tied to skills, so there is an Acrobatics Utility 2, and so on.
Superior Implements have been added, which have special properties accessible by those who have the Superior Implement Feat. Those special properties are akin to weapon properties (and I don't recall offhand how those are displayed in the MSE Power Cards). Let me know what other information you'd need, if any.
Ki Focus is added as an Implement.
When I open the Powers card set, I get the following message:
Unexpected Key 'or Dex vs. Ref'
Unexpected Key 'or Dex vs. AC'
Unexpected Key 'or Cha vs. For'
Unexpected Key 'or Con vs For'
When I open the Items card set and click on a Companion item, I get the following message:
parameter input has
no member 'Equipment Companion'
in function trim
in function isEmpty
in function iconFilename
in function iconMaskPngFilename
while updating styles for 'left icon'
The same message appears for Weapon/Implement Holy Symbol, Weapon/Implement Tome, Weapon/Implement Ki Focus, Weapon/Implement Dragonshard Augment, Equipment Familiar, and Immurements.
The other thing that PHB3 adds is Hybrid classes, which pretty much follow the same pattern as standard classes but some have both a list of Class Features and a list of Hybrid Talent Options.
I think that covers it in nutshells. If any clarification is needed, let me know. I'll check back as I can and offer what help I can [which won't be much for actually plugging in script for the MSE stuff--I've looked it over and my experience with BASIC and Turbo Pascal years ago don't give me much hope].
