Personally, I'm going to withhold judgment until we see whether Luke gets a decent amount of screentime in VIII. If we find out in 2017 that he trains Rey off-screen between movies, then it's going to hurt much more.
Also, I just kinda hope that the reason why Han is the central OT character in TFA is because it makes for a good story and not because Abrams/Kasdan/Kennedy are secretly Han fanboys.
Killing Han establishes stakes without losing too much plot significance (Han may be super popular, but he has no story ties to either the Jedi side of things or the political side), and it sounds like they're setting up VII to be his last ride.