Maybe I am just jaded, but with WotC doing a retread of D&D, using the same races and classes (for the most part - yes, I know some new stuff, but still...) - why not use that as an excuse to make some radical shifts to new ones? And whole new approach to it, as well.
One of the best things Arcana Evolved (and predecessor) did was to reimagine EVERYTHING, starting with races. I understand this is sort of a line in the sand thing, to hold on to 3.5 as a ruleset, and personally I like that you are doing so!!! But this is also a chance to really show the creative power of your staff, and really shake things up a bit.
I am not saying get rid of fighters, but really - what are barbarians/paladins/rangers except styles of fighters? Why not combine them into one class, with "paths" so to speak, letting players customize as they go? Focus more on feats as the tools to distinguish the character from his brethren, and a bit less on class features.
Same for casters - cleric/druid can be one class, with just different approaches within the class. Same for sorc/wizard, and bard/rogue. Monks... well, I am not a good one to ask about them, because I dislike the class, to be honest. But I suppose in with cleric/druid, just focused more on the mental and physical aspects of the class, rather than the spellcasting.
Beef up feats, with more trees, but also more unique one shot ones, that allow you to truly customize your character. Sort of a hybrid of a class based system, and a "skill" based one (like GURPS).
As for races, create whole new ones - ones that utilize the setting of your world a bit better. At the very least, turn some of the conceits that are just accepted as fact about a given race, and toss them aside, and paint new pictures for them. Elves are effete nature-loving spell-casters? Nope - they are radical guerrilla warriors fighting to preserve the natural order - with a favored class of ranger (or whatever you decide with the above). Halflings are mischievous wanderers? Nope, they are the keepers of lost knowledge, the high mages of the world - favored class wizard.
Is it true d20? Nope - but in the end, it might be something much much better!!!