Lots of tidbits from posts by Rich Baker on Gleemax added to the first post.
Significant info on the Swordmage
here.
Illusionists will have better Invisibility options than a Wizard (
source). They may use the Shadow power source (
source).
Necromancers are mentioned
here. They use the Shadow power source (Worlds & Monsters, and
here).
Rich Baker gives his guesstimate of traction for ten races from Aarakocra to Catfolk
here.
Goliaths will probably be in
4e Forgotten Realms, possibly with a spot in Faerun earmarked for them so you'll know where they're from when they're released (
source).
Half-Giants may be too similar to Goliaths (
source).
Rich Baker hopes to have Half-Orcs on
DDi pretty soon after the Player's Handbook hits (
source; note this is from January). He expects to see at least a couple of returning classes (Barbarian, Druid, Bard, Sorcerer) on
DDi by this summer (
source); later he guesses we might see Bard or Druid by late summer or early fall (
source).
Half-Orcs "imply a very ugly backstory"; they may try to change that (
source).
Gnomes, Half-Orcs, and Goliaths will be mentioned in the
4e Realms products, but not dwelled on because the rules for them will be a ways off (
source).
Bards, Druids, Barbarians, and Sorcerers will be in print in 2009 (
source).
Sorcerers will get flying a little faster than wizards do (
source).
"Multiclassing into swordmage is pretty easy for a wizard (and vice versa)" (
source). Swordmages like Int and Str (
source).
Genasi ability adjustments "don’t really support warlock all that well"; they have elemental manifestations, which are "really righteous racial abilities"; Firesoul and Stormsoul are two of the options (
source).