One of my issues with 4e is that their isn't a truly basic version of the game. 1e had great basic versions of the game by Holmes, Moldvay, and Mentzer and each of these were roughly compatible with the 1e game. 2e had a couple version of the basic game including the much loved Rules Cyclopedia.
Since 2e there really hasn't been a true basic version of D&D that was compatible with the in-print version. I am working on a basic version right of 4e that would be roughly compatible with the main in-print of 4e. Here is a link to what I have come up with.
Basic 4e D&D
Here are some highlights to my basic version:
1) It is not as tactically complex as 4e. In fact, it could easily be played with or without a grid (like previous editions).
2) I have removed the cleric class. The main thing that has separated the cleric from the other classes (in my mind) has been healing. Take that away and the cleric is mostly a warrior that can cast spells, and the healing isn't needed anymore due to the healing surge mechanic in 4e. See my multiclassing section below on more about this.
3) Feats aren't used, Instead it used Training Slots which are like feats but much more limited and easier to use. Basically training slots let you become trained in a skill, get armor and weapon proficiencies, and become Ritual Caster.
4) In 4e attack and defensive bonuses come from several different sources (e.g. 1/2 level bonus, feats, stat increases, feats, magic items) that essentially gives a character a +1 bonus to attack and defenses each level. So this version does away with those other things and just give everyone a +1 bonus to those thing every level.
5) I struggled with multiclassing a a little bit. I like it to be there by I wanted a simple system. The old basic versions didn't have it, but AD&D (both 1e and 2e) and 3e had it. The AD&D version was okay but I never really liked the 3e version. The 3e version does allow maximum flexibility but it never felt right to me (e.g. if a 5th level fighter chooses to take a level of fighter at 6th level now all of a sudden he can use every martial weapon and wear any armor -- that was twoo much of a jump for me). The 4e version is decent with its piece-by-piece version, but the 4e system requires the use of feats.
In my basic game multiclassing works similar to the 4e version. The idea is to use Training Slots to become trained in thing another class automatically gets. For example, if you want to be a fighter/wizard you can do it a couple different ways. Either start as a fighter and use Training Slots to become trained in Arcana and Ritual Casting, or start as a wizard and use Training Slots to get weapon and armor proficiencies. Either way you will never become a true member of the second class but you acquire some of its skills.
You can use this method to have a cleric-like character also. You can use your Training Slots to train in Religion and Ritual Casting and say your abilities come from your god (power sources are left out of the basic rules and are used for flavor/fluff).
I think having the flexibility to train in any skill with Training Slot allows a lot of options to create many types of characters.
Let me know if you have any thoughts or suggestions for my Basic 4e D&D.