In Keeping with the books:
*Stannis offers Jon legitimacy and Winterfell in episode 2.
*Jon becomes Lord Commander in episode 2.
*Jon beheads Janos Slynt in episode 3 and Stannis nods afterwards, apparently it's a great scene.
*Kevan is back and taking zero sh-t from Cersei.
*Kevan says he will serve as Tommen's Master of War if the king himself calls upon him but he will not be a puppet of Cersei's.
Changes:
*Ellaria is taking over Arianne's material
*Winterfell is introduced in episode 3 (with Sansa and LF going there). Littlefinger is still there in episode 4 but gets called back to KL by Cersei.
*Sansa's marriage plans to Ramsay is revealed in episode 3.
*Roose puts Littlefinger in his place and does a good job hiding Ramsay's dark side from the others.
*Jaime heads to Dorne after episode 1, arrives in episode 4
*Tommen and Margaery have sex, it's off-screen but you can still hear them f-cking like jackrabbits and Tommen post-coital looks like he's in heaven.
*Regarding the Dorne storyline, all in all; "As a die hard book reader I was okay with Jaime's part in the Dorne storyline, it all seems to carry out organically and Ellaria and Doran have nice scenes together. So far it's promising."
*Not a single mention of the ironborn or Balon, or Yara.
*Illyrio never even shows up.
*Brienne meets Sansa but is rejected by her
*
dies in Episode 1 (what the ****?)
*
dies in Episode 4
*
dies in Episode 4
*No hint of Davos going to White Harbor.
*Theon has zero dialogue in both episodes he appears in.
*Jaime continues to be pussywhipped by Cersei and wants her affection.
*Brienne has some speech about wanting to kill Stannis