Since floating this idea I have found out that their is already a big brother to the Arduino, the Sanguino - http://sanguino.cc. The Sanquino people have added the code necessary to support their hardware - based on the ATmega644P.
The Sanguino people espoused a philosophy worth emulating - inspired by Arduino. They needed something bigger for the RepRap project so they based it on the Arduino. Much the same as we did with the LEDuino by adding interfaces to the Arduino to make it more useful in other niches. The extended Arduino's are not meant to supplant the Arduino - they are meant to reach an extended market.
Trying to move the Arduino concept to other processor families would, in my opinion, mean a fork in the project. So far all of the things associated with Arduino, Wiring, Arduino-328, and a possible Arduino-Xmega are based on the AVR-GCC port of the GNU compiler. Whilst I would almost literally salivate to see something based on the LPC2378 (ARM7) with integrated Ethernet, USB, CAN and lots of other stuff with 512K of Flash, the Wiring/Arduino code generation system would need to change significantly to accommodate it. For example just for the USB port, what device classes do we implement? Sure, you need a virtual COM port, but somebody will want HID or Mass Storage before long. For the Ethernet, do we integrate an entire TCP/IP stack into the codebase?
As for little chips, like the ATtiny's. Well, just a few months ago a colleague and I were working away on a design project and chatting on Skype, we are located several thousand kilometres apart, I had used an ATtiny45/85 in a design. But we need maybe a little more code space and an IO pin or two more. So we looked at using the ATtiny84. But when you get down to it, the ATmegaX8 family is barely any more expensive! The ATmega168 costs around $US2.56 on 100's, the ATtiny84's are $US2.11. So we changed - we went for the ATmega168 we
- reduced the variety of devices we were using
- saved money by buying larger quantities
- reduced our coding efforts
- opened the way to using the Arduino approach
- spurred the development of the LEDuino
and all of that for about 40 cents per board.
In my professional life right now one issue I need to address is "platform creep". We are finding that over the years we have collected an array of different processors in things and we have different development environments, different assemblers/compilers, different limitations all resulting in lots of extra cost and many headaches. Within the Arduino movement the move to other platforms would produce similar results. That would inevitably result in the 'dilution' some people have referred to.
I am not against platforms using bigger processors - I design with other CPU's both conventional and soft-core every day. But so much of what the Arduino movement is all about isn't addressed by the 'big' end of the market. And as for price point, well for $100 you can get an AVR32 based board with Ethernet ports and Linux. For $145 you can get an ARM-Cortex-A8 based board with Linux - if that is what you need. But the success of the Arduino, BASIC-Stamp and a number of other things like them is due to the low entry cost. And the Arduino philosophy of low hardware cost, simple replication and an easy to use development environment is VERY VERY hard to resist.
Sorry for the longpost, I hope it isn't TOO boring.