Seminars will always suck until the organizers aren't stuffiing it with their cronies/supporters and getting an ironclad insistence that panelists cannot talk about their own products during the seminar, except perhaps for a brief mention at the beginning and end.

Likewise, an agenda/outline for each seminar, a moderator who has some idea of the areas of expertise of each speaker on the panel, and strict enforcement of time for each panelist would go a long way toward making the seminars a useful experience.

There are definitely ways of addressing the issue of panelists pimping their own wares... providing alternative ways/places for the panelists to talk specifically about their products/services, recruiting on basis of knowledge instead of who knows who, that sort of thing.

When someone actually cares, it will change. Not before then.