What's the impact of IEEE PoE standards on industrial applications?

Ian Verhappen wrote that Power over Ethernet (PoE) certainly removes the single-cable constraint to using Ethernet in the field (see in "PoE-The Missing Link"). The challenge faced by PoE for automation applications is that the 802.3af standard specified a voltage of 48 Vdc, while this industry has standardized on 24 Vdc. So far, at least one industrial Ethernet equipment supplier released a PoE splitter with a 24 Vdc output.

The IEEE PoE Standards Continue to Evolve, so what's the impact of these "new" IEEE standards on industrial applications?You can read Verhappen's article "PoE -- The Evolution Continues" to learn more.