Had a bunch of timeout alerts. Some machines of an application server array have the packet drop issue. ELB says that everything is peachy. Folks, we're experiencing yet another "EC2 flavored SNAFU™".
Initial though was: f#*k, I ran out of network I/O, since EC2 simply states "low, mid, high" as performance specs, therefore some proper planning is out. Turned out that with load avg under 0.02 on all machines, the I/O wait wasn't to blame. Average response time, per Pingdom, went up from 170ms to 450ms. New Relic isn't happy either. I guess we should all thank Amazon. Again.