This old post on Campaign Mastery has some interesting background material. It's obvious that Pathfinder has filled the "AD&D reborn" niche, while it seems that Essentials (and Gamma World) are searching out a way to evolve the Basic D&D mindset to a modern culmination.
Although my title here is a bit of a joke, the thinking I was doing about D&D has morphed into asking what D&D could look like if the CCG aspect was fully embraced. (I hate the 'collectible' aspect tho, so i'm ignoring that. I like to see what i'm buying.)
- Characters are built as decks of cards
- Each advance (level) allows a choice of card to be added to your "deck"; presumably, you could "level up" in Elf as easily as in Barbarian or Thief
- Artifacts & "Magic Items" are cards as well; perhaps more focused/limited than level cards, perhaps not
- Spells are item-like cards, as well; Vancian-magic Wizards would assemble a Spellbook deck, Sorcerers would just have the spell cards as a permanent part of their character's abilities
- Unlike 4e, cards are generally not exhausted (items and spells can be exceptions)
- Cards are easily manipulated, sorted, & can act as physical objects ("show me")
- Cards can be illustrative - going so far as the Paizo NPC Cards, with a picture on the front and text on the back
- Cards make things real; this is great for any fictional thing which can be traded, lost, or expended; (note that if aspects of a character can be exchanged or changed, then cards are excellent tools, as well)
- Cards make it easy to "put the pieces together" in building a character
- Cards allow random generation to be easy and sensible (including allowing themed decks and role protection)
Things such as Quest cards. I probably shouldn't use that MMO-inspired 4e term; I don't quite mean the same notion. A Quest is not something the Iconic Old Man gives you, at least not just that; it's an intrinsic part of your character, like a class or spell or treasure. It's like a BW Belief - you can change it, you can discard it, you can complete it, you can have more than one, but when you have it, it's always in the forefront of play. Quests allow a character's goals & purpose to be put front and center, and be rewarded; taken the other way, 4e style, they also allow the GM to give the party priorities and hooks in a memorable, concrete form.
Another similar idea would be to introduce "Personality Cards"; these are essentially role-playing prompts (perhaps with a baked in mechanical benefit, perhaps separate from the XP system, perhaps not). Like a Tarot card, ideally they would be open to interpretation; if not, then experienced players should be able to easily make up custom Personality Cards that follow a set of guidelines. These would be great for drawing up randomly, and working into a character concept.
This article by Robert Schwalb discussing classes & subclasses is relevant to any thoughts about class designs.