Is my AEBS dual-band dead/dying?

Here's my setup. I have an AEBS connected to a Time Warner Cable modem. The ethernet ports go back to two Windows desktops and an Iomega NAS. I run two MB Pros, an iPod and an iPad wirelessly, and also stream Netflix through a Sony bluray player. I have a few Airport Expresses to connect iTunes to speakers various rooms. The Iomega and bluray are relatively new, within the last month.

I've had the AEBS for almost two years and have had excellent throughput.

We streamed a movie on Netflix on Monday and everything worked perfectly. Ten minutes later, we tried to stream a second show and BAM! Slow start up, impossible to watch the movie due to constant buffering.

I ran the CNET speed test and my dl speed was 300kb/s, less than 5% of what it used to be. Went through unplugging, re-plugging, downgrading the firmware, re-upgrading the firmware. Don't think its a firmware issue because I upgraded back in December with no issues.

Checked the network settings on the bluray player and all my devices and they are fine. The throughput on the windows PC that received the ethernet connection back from the router has also slowed to a crawl.

Any suggestions, or should I stick a fork in my router?

Thanks,
Mike