Needs more ladies to break up this sausage fest.
That was one of my first thoughts too. The picture looks kind of awkward with the sheer amount of dudes there and only three women, one of which is a producer.
I heard that Adam Driver came to J. J. Abram's attention when Abrams saw an interview about him that said he had to work out every day because he felt the need to physically destroy things. So, here's hoping he plays a bad guy. He's also got a creepy voice so I think he could make a good villain.
Andy Serkis's presence always gives you strong odds that a main character will be completely CGI'd, which makes me nervous in Star Wars terms (J.J.B.), but then again I love his work as Gollum and Caesar, so overall I'm looking forward to seeing what role he plays.
I just hope that each of these actors is not a main character; it would be too much. I assume Abrams wants to keep the 3PO/R2 motif, so those two are already accounted for. I kind of doubt Chewie will be in it all that much because of Mayhew's health/age. But then your other true main character were only four: Luke, Leia, Han, and Vader (I suppose you can make a case for Lando). I think a lot of what made the originals work was the focus on the core trio's relationships to each other, so I hope Abrams doesn't have too many characters vying for us to care about them.
My guess would be the mains are Boyega, Ridley, Isaac, and Driver. Serkis with a side part as a Yoda-like character. Von Sydow as a Moff holding the Empire together. Gleeson as a space leprechaun.