Well,
I have played DnD for like 20 years now. I started with ADnD and move forward up to 3.5.
I own a lot to that game, specially for the character development and archetypes conceptions. Not to mention Larry Elmore style art.
I believe we all must learn a LOT from WotC, specialy about they text revision and editing, and diagraming of their books. HARP has lots of problems when comes with uniformization of game terms (Ex: Hits, concussion hits, Endurance points etc.).
Mathematicaly speaking the 3.5 is awesome, when compared to other editions of the game.
But I realised DnD 3.5 has become an elaborate Battle Chess Style Game. Curiosly returning to his origin, when it evolved from War Game to Role Playing Game.
The game lost much of his soul, when the DM became a Mediator of rules. In fact the DM became just a story teller, since they have rules for almost every situation, so you don?t need much DM ruling anymore.
Then the "Cold War" begun. Combos and more combos developed by power players started to be countered by new official rulings and more combos were created in response, to the point I do not recognize the arquetypes anymore. No one play a fighter for example, becuse it?s considered by the "experienced players" as a week class. On the other side every character i have sem on the gaming tables was developing "some levels as a fighter" becuse of the short terms benefits of a fighter on levels 1-4.
In short: the game became a mathematicaly well balanced unrecognizable mess.
I don?t know much abou the 4e yet, but my expectations are very low.
So all things considered I believe it will be good for HARP and RM.