I don't track this, so I don't know if this is normal, but it appears to 8 major routers [internettrafficreport.com] are down today.
jdMorgan
3:53 pm on Jul 10, 2007 (gmt 0)
Those aren't really major routers, though. They are nodes located just off major internet backbones, though. It's hard to tell if this indicates a backbone problem or if those datacenters are just down without further digging.
In at least two cases, the problem appears to be DNS lookup failures.