Gary -
Yours is only 10 years on the tub. Mine has the full 25 years, but it's a later model. Those tubs run close to $500 for a new one, but that rust is certainly repairable. Robert has done restorations where tub rust through was an issue, and I'm sure can give you the procedures and compounds to use to do the repair, if you're comfortable tackling that job. It probably involves removing the pump and motor assembly, and probably the heating element. I don't know of a way to fix that with everything in place, though maybe some of the folks on here have an idea?? It looks like it will eventually eat through there.
If you look under the machine, do you see any kind of water seepage around the pump area or from where the heating element connects through the tub, or does the rust appear to have started to eat through the sump from the bottom? If you see any signs of seepage, stop using the machine to prevent damage to the motor. I don't know what other advice I can offer, but my old Waste King rotted right through the interior around the sump, and dripped right into the motor. I only knew it was leaking because a water spot appeared on the ceiling below the dishwasher....took about two weeks to destroy the machine. Didn't catch it in time.
btw, my superba has rack rust in the exact same place as yours does...lower rack is fine, but the upper rack rails are rusted like yours. I know there is a kit you can buy to repair that, or at least seal it so it doesn't get worse, available at Sears or Homo Depot...about $8.