Oh sorry, nevermind. I forgot that WiFi is NOT working in 4.3 and that's why I wanted to try 4.4, because I'd heard drivers had been added for multiple WiFi cards. But, I guess it was not added for Surface Pro. Dangit. :(
I emailed Marvell customer support to ask if they could help us with a driver. You can email them too here: http://www.marvell.com/support/contact/cust_support.do
Android-IA 4.2.2 has WiFi working in the Surface Pro now that I think of it. So someone who knows how to work with the Android kernel can borrow the drivers from that one and recompile it into Androidx86 4.4 for us? Android-IA: http://rerede.com/thread-12041-1-1.html