The new arduino, the DUE is out today.
Its a 32bits, 87Mhz !
A good toy for us.
The current IDE (Arduino 1.5.0) for the Due is a beta version. It doesn't even support interrupts. I have installed it and try to compile some of my existing sketches. Didn't have much luck. Almost all "third party" libraries will have to be rewritten. The code the compiler generates is huge compared to AVR 8bit. The blink sketch is almost 10kb :D It has 512kb of memory so that will probably not be an issue. The biggest issue will be that it runs at 3.3V and some of the output pins can only give 9mA max, other pins 15mA. So you will have to be careful to connect stuff to it. If I look at all the robots posted here on LMR only a tiny portion could use a faster 32bit arm micro controller. And if you want to do advanced stuff like video processing (openCV for example) you need a micro processor that can run an operating system like the Raspberry Pi or the Beagleboard. The Due is somewhere in the middle.
A 5V 8bit AVR micro controller is still a good solution for many things. It can easily be pared with lots of electronics and there is lots of software support for them (libraries).
Anyway, I will be ordering one for my Arduino collection :)
I could use the extra memory. I find you can try and do too much on the current products. I have had to cut corners on some of my code to get it to fit. Reminds me of the old days I was programing on my Commodore 64. Smaller was better.
the arduino IDE will be but there seems to be interest in using existing ARM C compilers with it anyway