According to Morgan Campbell, via Twitter, Cecil and Roenicke are being dispatched to Vegas.
That means Eveland and Tallet in the rotation and Accardo and Valdez in the bullpen (until Carlson get's his innings in - two weeks at most).
A lot of popular sentiment had been that Cecil had pitched well enough to earn a spot. His job now is to maintain a positive attitude and not get pissed and distracted by the demotion. He can go down to Vegas and force the team's hand if he stays focused. He's on the clock too. He needs to make that case BEFORE Zep (and McGowan) get's healthy and ready to pitch. But then, my guess is that Tallet and possibly Eveland as well will help make the case for the kids in time. They might start off well, but I think they will be exposed over time.
The other thing here is Accardo. As much as I'm ready to watch Cecil grow, I'm happy Accardo avoided the "options" shaft for now. Of course, Clarance can still let him sit out there and rust so that being in the majors will do him little good, but hopefully he can focus (without trying TOO hard) and at least make himself more attractive to teams looking for bullpen help when he does get out there.