Arduino's aren't used much, because genuine electronic engineers, don't like the software to handle the setup of the µP entirely. The want to make use of the possibilities that are given them by Atmel. The arduino is a great tool to whip up a proof of principle, but for production hardware, the overhead is way to massive --> so you need a more expensive µP to do the same task. There is no way to change the bootloader, etc
The system hasn't got enough flexibility for a professional, but for a novice/hobbyist, it is a great introduction in the exciting world of electronics/microprocessors.
