According to a Discovery press release, the upcoming 4th episode of season 3 looks to have a synopsis finally!
They also have the 3rd episode listed. It's looking like the Zap2it list is legit.
Head on down past the break for it.
Thanks to Kein for the heads up!
One Bad Apple:
Air time: 10:30-11 a.m (Later than usual for both "Too Many Pinkie Pie's and this one)
The Cutie Mark Crusaders are crushed when Apple Bloom’s cousin, Babs Seed,
rejects their invitation to become a fellow Crusader and instead becomes a bully determined to make their lives miserable.