John - thx as always for the engagement.  Regarding your point on a conversational style of presenting:  Indeed I have seen this and have even engaged in it myself when presenting.  One good twist on this I've tried is when people ask questions of me during my presentation.  Before answering I often turn it back to them and ask others in the audience for their points of view on the question being asked.  Quite often you uncover the latent expertise that sits in the room, amongst the very people you are presenting to.  Everyone gets involved and is eager to share what they've learned.  It further enriches the overall learning process.
Regarding your question on varying learning styles - you are 1000% right.  Some scholars refer to this as situational learning - similar to the situational leadership style definition made famous by Drucker.  I find that if you switch up the approach to learning, it definitely keeps folks more engaged.  And you need every trick in the bag because multiple studies have now confirmed that the average attention span of an adult is, are you ready for this, 8 seconds!
Thx John,
Scott