subway:
However, standard 8-bit AVRs are used all over in successful industrial and commercial products, and this has been the case for many, many years. – wjl Oct 15 '11 at 1:31[/i]
microcontroller - Why are Atmel AVRs so popular? - Electrical Engineering Stack Exchange
There was a thread a while back about products that folks had torn down for parts or whatever and found Atmel MCUs inside. I happen to know that they are used in automotive applications. I expect that they are very robust indeed. I would not expect MCUs from Microchip, TI, Maxim, NXP, ST Micro, etc. to differ significantly in that regard.
Arduinos are "prototyping platforms" (first sentence on the home page) so right there that tells us they are not necessarily meant for deployment in industrial or even commercial applications. That said, they do the job of prototyping platform very well. Even so, I would still expect them to be very robust in reasonable environments.