Yeah, many datacenter's were effected by this, including GNAX, our provider, but after just a couple hours, they re-routed traffic. IMHO, they did a hell of a job!
But yeah, basically Cogent is sending more traffic over Level 3 than Level 3 is sending through Cogent, which means L3 is getting ripped off basically. They have been warning Cogent for a while that it was going to happen, but they never acted, so in the end Level 3 disconnected their services, causing a lot of problems world-wide.
Just yesterday, Cogent and L3 came up with an agreement, and restored full peering.
I wouldn't recommend Cogent, but it's a cheap option to go if you're on a limited budget.