Satyrs- I think these would be great. Another fey race.
What's wrong with re-fluffing Tieflings or Eladrin or, I dunno, Halflings as Satyrs? (in fact...)
Goblins- Why haven't these been done already? Good rogue possibility.
They're around, just not very well supported. Which points to the bigger problem in 4e -- too many races!

Also a problem with too many classes. They can't support all of them!
Half-ogres- A race with the possibility of becoming large sized through feats.
What's wrong with re-fluffing minotaurs or goliaths or, I dunno, Bugbears as Half-Ogres? Is it just that you'd like to see a race that can get Large? Because that has some mechanical/design issues (such as: Does the DM need to now design the game so that every encounter map has at least two squares worth of width for me to move down?) that are kind of impossible to work out without a brand new system.
What's wrong with re-fluffing gnomes or halflings or, I dunno, Eladrin as Sprites? Is it just that you'd like to see a race that is Smaller Than Small? Because that has some mechanical/design issues (such as: Does my armor cost as much as outfitting a Goliath?) that are kind of impossible to work out without a brand new system.
Dreamlings- creatures from the Plane of Dreams, who have illusory powers.
Know ye of the
kalashtar, creatures from the Plane of Dreams?
Mutates- Humanoids touched by the Far Realms who are mutated, feats for different powers based on mutations
Know ye of the
foulborn, spawn of the Far Realm?
Merfolk...Kronosians...Witchlings...Hobgoblins...
Limited campaign scope, limited cultural scope, have you heard of Eladrin?, and See Above for "Goblin."
Don't get me wrong. These are all solid ideas for characters. But I don't know why you'd want to make another
Bladeling, another brick that sort of sits there and doesn't get played with.
But I don't think 4e is done entirely with "new races" of one stripe or another. However, I don't think we're likely to see "new races" wholesale. After Essentials, the design team seems to have a new appreciation for integration, of creating things that are future-proof and past-usable. See: the Essentials classes (the Mage is a Wizard, not a new class. The Hunter and the Scout are both rangers, not new classes).
We might see a "new race" that thinks broadly of the concept of race rather than narrowly. An "elf" that can embrace eladrin, wood elves, drow, and half-elves all without giving you four different stat blocks, perhaps, one that can be expanded in the future with a simple brief addition rather than an entirely new racial write-up, so that all elves can cull from the same broad spectrum of abilities, and only vary subtly, in detail.
Or not. I dunno. There were some ideas getting mentioned here that might have appeared in those books that may now be cancelled, so it's anyone's guess.