I personally dislike the idea of Archer & Bard, but in some ways it does make sense. FFXIV still seems to be about producing hybrid classes.
The mobility that Archer has, is what Bard needs as well. Other classes just don't have the time to run around like a mad man.
It's also a nice excuse to lower the damage Archers do a bit, since it's not just a damage dealer anymore. Which might prevent the Archer only parties at endgame. (There is no doubt in my mind that those come back when their weaponskill damage gets fixed)
Ofcourse when the beast named Archer is tamed, Musketeer will make it's entrance...