What I think will happen on Degrassi based on the 'Bite Your Tongue' promo:
1) Katie, Drew, and Bianca
So, Katie got back from rehab. She changed her look, hence the new clothing and hair. As we saw last season, Drew's family and Bianca are becoming closer, and Katie gets jealous. Bianca and Drew end up kissing again and Katie eventually finds out. And (hopefully) Drew and Bianca get together.
2) Eli and Becky
I think Becky comes into Degrassi thinking she's the best director/writer. She ends up working with Eli in the Degrassi Drama Club. They argue a lot and the play won't seem to work out as planned. But, opening night, it's a success and they bury the hatchet.
3) Degrassi Hockey Team and Tristan
It seems like the Tristan's' main problem is Mike Dallas. He seems to bully him and is a homophobe. He gets the rest of the team to join in on the homophobia. And, I think Campbell Saunders, another new student, isn't all that bad. He just wants to be accepted and liked by the rest of the hockey team, especially Mike.
4) Maya and Campbell
When the Degrassi Stargazers have their first meeting (Maya the president), Campbell joining is a shock. Maya doesn't think that he is serious and blows him off. Soon enough, they become close, and develop feelings for each other. Meanwhile, Tori is telling Maya it's not a good idea. She says he is bad because they hockey team is mean to Tristan. At the same time, Mike (and either Jake or Luke {Another new character}) feel the same way. They believe that she is a loser freshman. They secretly date for a while, but either he messes it up or their friends find out. They ignore each other for a while, but will end up together.
5) Everybody!
When everyone is together, they put on their fake smiles and say fake greetings. Then, the camera snaps and everything goes crazy. I think it shows how each storyline is somehow connected. It also shows that this season, Degrassi will indeed fall apart because of all the drama. The drama shown is a lot, but there are still lots of storylines and characters not included in this promo. The part that stands out the most is that Clare is (or tries to be) above the drama. Ultimately, this season, Degrassi WILL fall apart.