The debate about running shod vs. barefoot rages on.
However, midfoot-forefoot striking is more effective and less liable to cause injuries. When you shorten your stride and increase your cadence (turnover), your feet tend to land closer in line with your body rather than way out in front as they would with an extreme heel strike. As your footstrike becomes closer in line with your body, it is more natural to midfoot-forefoot strike and toe-off.
The main benefits of midfoot-forefoot striking are increased propulsion and efficiency (you don't lose as much kinetic energy as you do when you heel strike and rock forward), and less risk of injury, since impacts are less forceful.
I have personally modified my running style to become more of a mid-foot striker, with increased toe-off. Though I have reduced heel-striking, I haven't eliminated it completely (I can tell by looking at wear patterns on my old shoes).
That said, (minimal) shoes are the best way to go. There are many surfaces (gravel, asphalt, etc.) which are simply too harsh/sharp/hard to run barefoot on, though I agree that running barefoot on softer surfaces can be ok.
The most elite runners in the world still wear running shoes, and many of them still have a slight heel-strike. The day I see barefoot runners winning major marathons in close to 2 hours is the day I'll change over.
Check out the photo on this book cover - at least 4 of the runners are heel-striking to some degree: