Actually I'm already aware of that, I just didn't make it very clear. What I meant by the end of that sentence, "...and yet at that point it may not add much to the game in exchange," was that doing work like motion capture and modeling for the two new sexes isn't for just the few of us that are playing now, but the multitudes more they hope to pick up upon "re-launch" for the PS3. Doing that same work for new races later on doesn't seem like it would have as much benefit as there won't ever be another time they have the potential to greatly increase their number of players and thus have enough people use the new ones.
Padjal actually have more of a problem being implemented than beastmen or any "new" race would, from a lore standpoint. There are only supposed to be a very small number of them (<5 IIRC) because they are "chosen" by the Twelveswood/elementals outside of Gridania. They're not a truly separate race of people that produce offspring; they're regular people that get chosen, grow horns, and stop aging.