There has been a great deal of exactly that feedback from attendees (including me) and Chris Anderson is definitely hearing it -- he addressed it at length from the stage twice this year. However, he seems to think that is a necessary side effect of producing talks that will be viewed millions of times (I think he said ted.com has hit a billion views now). I'm not sure I agree, but in any case I enjoyed it more back in the day when you never knew if the next talk would be an epiphany or a train wreck!