I also had this same problem this morning with the Broadcom card. I lost my service console connection, but could still ping my VMkernel IP (SC and VMkernel are in vSwitch0). How is this possible ?
This hit me too, and I have am using the tg3 driver. I have the Broadcom 5703 and 5704 cards. The strange thing that I can't figure out is that I have 2 NICs on each vswitch and it only affected vSwitch0 (which had my service console and 1 portgroup with vm's on it).
The posted fix worked great. We'll see if support has any ideas.
This took out my whole training farm at the exact same time. I sure hope this isn't some periodic bug that crops up again.