Comcast has sued the FCC to overturn its order to stop slowing down P2P traffic, as was widely predicted. Even though they're fighting to have the FCC's ruling reversed, it's actually not so they can go back to mucking your P2P funtime—no, they're already way down the road of slowing down heavy users' entire connection to DSL speed for up to 20 minutes, with data caps beginning in October.
The point is to rollback the FCC's power: Comcast, and the rest of the ISPs and telcos, don't want the FCC to be able to tell them how to manage their networks. That order is previously uncharted territory for the FCC, and if it stands, it'll set a precedent that grants them fairly broad powers to look over the shoulder of ISPs, and effectively, a strong hand in the shaping the future of the internet.
FCC Chairman Kevin Martin has already responded to the suit, saying that the FCC had "put Comcast on notice" back in 2006 that it'd look into complaints about Comcast gumming up their network without properly notifying users, yet "Comcast nonetheless chose to close on that deal." For Martin, as usual, the mantra is about informing users, not so much about rules and regulations—whether or not that's just his public strategy to get the rules in place is debatable, but it is his standard script.