I missed the first twenty minutes, having to run to check out of my hotel at noon, which is when it started...from what I understand, all I missed though was product spotlights...and we get that quicker here than from any official sources anyway.
A friend and I managed to get some questions in during the Q&A, which took up the majority of the seminar. The ubiquitous question about seeing something beyond Faerun was asked, with the usual answer. However, I was surprised to hear them say that a few FR adventures were in the works (and they didn't mean in Dungeon either) - that was shocking to hear.
Beyond that though, I found the seminar to be something of a let-down. The questions were, for the most part, ones that get asked every year, and the product showcase is, as I mentioned, nothing special for those of us here on EN World. All in all, I don't think you missed that much.