Found this on kickstarter, looks quite interesting although I'm sure it's not the first time its been done. It will be interesting to see where it goes. https://www.kickstarter.com/projects/814866572/xlr8-arduino-compatible-fpga-based-application-acc
from the kickstarter page:
What is XLR8?
XLR8 is a drop-in replacement for an Arduino Uno, but with a twist. It is an Arduino-compatible board that uses a Field-Programmable Gate Array (FPGA) as the main processing chip.
The FPGA provides a reconfigurable hardware platform that hosts a clone of an ATmega328 microcontroller. The FPGA also provides the ability to implement custom logic that accelerates specific functionality known to be slow or otherwise problematic for the standard 8-bit ATmega328 microcontroller.
The FPGA-based hardware acceleration and offload provided by XLR8 results in significantly improved performance in the same physical footprint and using the same tool chain as standard Arduino Uno boards.
If you have a project that's using an Uno, you can swap in an XLR8 board right out of the box, and it will just work. You won't even know you're actually running your sketch on an FPGA, at least not until you fire up one of the accelerated functions…and then the magic happens.
Bottom line: XLR8 provides a solution to accelerate your Arduino-based applications and projects.