Thoroughly amazing. After 6-7 weeks of calls -- hours on the phone with Samsung -- and an acknowledgement from Samsung that the firmware would not be updated/the app would not work, last Friday Executive Customer Relations finally authorized an exchange.
Long story short, I was given a credit at HHGregg equal to my purchase price. Went in there this evening and plunked down an additional $500 for the PN60E7000 (I got a really good deal last June) -- it's to be delivered on Saturday. Getting ready to go to bed, I check the forum for the first time in a week and see the post before mine. Five minutes later, the firmware is updated and MLBTV is working once again.
Part of me wants to throw a rock through the screen and await the new TV on Saturday.
Recognizing that is a bit emotional and foolish, and I otherwise really love this TV, I think I'll just cancel the order for the E7000.