It's very likely that there will be at least one new race. If you look at the smaller character in the back in the far left of the large scrolling image on the teaser site, you see a small child-like character with small horns. I believe there was a race like that in Final Fantasy Tactics.
Edit: Here you go, the race was called Gria. http://finalfantasy.wikia.com/wiki/Gria
They also first appeared in Final Fantasy Tactics A2, not the original. Edited, Jun 3rd 2009 4:14pm by OddysseusOfRamuh
**** I'm not sure how it could be anything other
than a Gria. Cropped image
The Gria are a small-bodied draconic race, complete with dragon wings, tail and horns. The Gria are more proficient in physical attacks rather than magick in combat. Their ability to fly seems to allow them to ignore the "jump" stat, giving them an advantage in areas with high terrain, and allowing them to easily get behind units, as they can simply fly over them rather than try to walk around them. And unlike units equipped with Faerie Shoes, which use teleportation to ignore the jump stat in a similar fashion, Gria are immune to falling damage; If they are knocked off a high cliff, the Gria will use their wings to slow the descent.
It is never made clear if the Gria are entirely female, or if they have male members, though the game hints at them being made up of females exclusively due to the lack of male Grias to appear. Note that the Gria are not to be mistaken with the Aegyl.
Not only do they match the description to a T, they can easily be the "counter-balance" for having a Male only race (Galka) and a Female only race (Gria, as compared to Mithra), thus allowing Mithra to be played as male, which is heavily hinted at with the male Mithra at table + boyish looking Mithra in trailer.