Tools wise there is hole here that when it gets filled will be pretty impactful, I'm talking about the Arduino concept implemented with the ARM Cortex M4. This is because the costs of the chips are low, but the tool chain support which has been part of the foundation of Arduino's success aren't there yet. Now bits and pieces do exist, if you get Atmel Studio (Makers of the ATMega and SAMx ARM chips) you will see they have a gcc toolchain for ARM that is as self contained as the toolchain for AVR (and by self contained I mean that it is a 'bare bones' tool chain and the resulting binary includes the bits normally supplied by an OS like startup, initialization, and memory management)
The part that is really cool though is that you can build computers out of these things again and they are moving into the space being left behind by Windows/Intel and Apple becoming more application delivery appliances. One risk I see though is that a lot of poor security architected embedded systems are finding their way into the routable Internet. That can be funny when port scanning software turns your lights on or off, but its a risk none the less.