Obviously I'm very excited for this season and April cannot come any faster, though I do want to talk about something that's presented in the trailer that is very spoilery, so...
[BOOK SPOILERS about a specific character]Based on this trailer it definitely looks like they're gonna do the thing with Shae, which is unfortunate and sad because I loved what the show did in expanding her character and having her be protective of Sansa. It's a change that has been well-received because Sansa doesn't have many people who are on her side while trapped in King's Landing and Shae does seem very genuinely concerned over her well-being. Unfortunately, being this series, all good things must come to an end and that means Shae will meet her inevitable fate. :(
Considering how they've set-up her character on the show, it would be difficult to execute the scene the same way, seeing as how Shae has mentioned her devotion to both Sansa and Tyrion. I'm thinking that she either goes to Tywin to try to make a bargain (for either Tyrion or Sansa, or both), and he either already knows about her or has his suspicions and ends up killing her, which is when Tyrion enters and upon seeing her dead body kills Tywin. Or the alternative is that Tyrion walks in with her on his father's bed and, thinking the worst (since everyone is already out for him anyway), he kills her out of irrationality before she gets the chance to explain herself, and then kills his father.
The former seems more plausible given the continuity of what the show has set-up between Shae's relationships between Sansa and Tyrion. I just remember what Tyrion said about killing for Shae, and then later Shae saying she would kill for Sansa, and it just makes perfect sense to have it be that scenario than any other one.
Regardless though, I would still rather they change all of that altogether and just have Shae take Sansa and they'd run away from King's Landing together and never look back. But alas, ASOIAF is not about the happy endings