The fandom has pretty much already adopted the name "Pipp" for the pegasus that joined Izzy and Sunny on the sheets last month. Blame that early 4chan leak for that one. Apparently it is yet another thing that is now confirmed, at least according to a trademark that Hasbro recently filed.
Of course, it could be a different character on the mane-team, but considering all of the evidence so far I think we can probably put this one to rest. I wouldn't mind a screwball though. Bring it on Hasbro!
Update: We are getting reports that there is a Zipp Storm trademark too. Looking into that one!
Update 2: Zipp Storm has a separate trademark on USPTO.gov. We might have two separate characters, or Hasbro wasn't sure what her final name would be.
Update 3: We Also Have "Princess Petals!" My guess is we have two characters, Princess Pipp Petals up there, and another yet to be revealed character named Zipp Storm
Thanks to Emperor Sombra and VcSaJen for the heads up