Forget music halls -- Twitter thinks morning TV talk shows are where it's at for product announcements. It used The Today Show last year to unveil a profile page redesign, and we now know it will rely on Good Morning America this Thursday to unveil something... "big." But what does that cryptic clue mean? While logic would suggest Twitter Music given its semi-official status, we could also see TV in expanded tweets or something entirely unexpected. We'll keep our eyes (and possibly ears) open.