I don't know why he put "boring" in his title, since nobody wants a boring sermon, and he certainly doesn't defend boring people. I think "long, boring" is meant to borrow from the common perception of long sermons.
I think it all depends on how a pastor approaches his teaching and how the community has been trained to receive it. Training is important, and over time, an impatient congregation can be weaned off of sitcom-length (and depth) preaching.
Good sermons, as David Hansen says, are like crushing the serpent. You're doing spiritual battle with Satan and with hearts.
Good sermons also feed. I know it's not popular in the SuperDuperRadicalExtreme Conference church crowd to talk about feeding people from the pulpit, but good sermons should be feasts. Enough for everyone, too much for some.
The Word of God is life or death stuff. Do six bits of advice, five illustrations, and four verses reflect that?
I am not saying that you can only have this experience in a sermon. Other people have made a good case for the centrality of preaching, so I won't rehearse them here. But I am suspicious of arguments that make the rate of information retention the deciding factor in how we teach the church.
The notion that, because people have short attention spans due to soundbites and entertainment, our churches should therefore continue to nurture short attention spans with soundbite sermons and entertaining "worship" is lame.
(HT: Transforming Sermons)