I watched the season premiere on the PBS Kids channel. I have to say, I was very, very impressed with the show. The opening theme has been redone already, but the additions were very nice. And of course the sequence playing along with it, with the chalk, was very cute. Nice to see Murray, of course. Big Bird's street scene was very nice, and we almost saw the entire human cast during that sequence, if not all of them. Abby's Flying Fairy School, like others have said, was very cute and funny, but it seemed to be a strange fit. Bert and Ernie's Great Adventures, my favorite new segment of the show, was also very good. I was happy NOT to see Murray Has A Little Lamb because that ran every show last season. Elmo's World, of course, drags the show, but that cameo by a certain character was very shocking. Earlier that day, my parents and I were talking about SS's 40th season and how he wasn't able to be on the show anymore, what a coincidence! Great show! I wasn't able to catch the end, though.
EDIT: Just realized that the Elmo's World short was the only thing not in HD but it was produced for last season, not any season before! Obviously Sesame Workshop now has the rights to use Kermit!