Interesting, we've patented something similar which will be rolling out Jan 2014. Ours basically rotates two payment gateways of two separate MSP's. In a nutshell it allows us to cap the processing charges on any card with an interchange rate above 2.25% down to 2.25%, even AMEX. We've added surcharge capability but at the moment based on First Data reports the demand for surcharging is very low.
If your saying MSP's are threatened by your solution I'm assuming you've build a proprietary gateway to deliver your "plug in"?