Let me start of by saying reading this post by James Enck may cause your heart to skip a few beats if you work at Level3 or are a customer who relies on them, or has built budgets and pro-formas based on how Level3 charges you.
But it goes much deeper and you MUST read through the various links that other bloggers have gathered to get the whole picture.
It spells out a plan by Qwest to basically undo the concept of interconnection agreements that make it possible for VoIP's underlying super carriers, like Level3, a network which was built to be a VoIP and IP carrier from day one, from having a future, and with it, trying to hold onto the legacy's phone network's access to PSTN customers. (And you wonder why Covad and Earthlink want to execute on an air game vs. be dependent on a ground game.)
The line from Gordon Cook sums up a lot:
Net Neutrality is a skillful diversion to draw our attention there
while Qwest, ATT, Verizon and BellSouth still the knife in at the court
and PUC level and kill off the remaining services they don’t control.
By reading through the brief filed with the Arizona Corproation Comission it becomes clear and could not have been easier to understand the motivations behind this, and more importantly why Level3 is taking this matter so seriously. The ramifications are great, and if you're a VoIP player you want to know what this could mean to you, and how it would affect your decisions.