^ i think kurt was just shocked. He probably wasn't expecting it at all from blaine.
I seriously think Sam and Mercedes is just a "we have two gay guys, a gay girl... why not through in an interracial couple in the mix since artie and tina broke up a year ago". I am interested to see how they communicate with each other and how their relationship develops in season 3 though!
What I want to know is the entire glee club juniors about to be seniors? If so, then what the eff! They should have started the show as they were freshmen. Get at least 4 seasons out of them. I don't think the show will last if next season is the last for the cast. Now if they follow the glee club to college, that could be muy interesante!