How can we know? BFL doesn't even know what it will look like inside.
What are the "guts" of the other already released mining chips?
Where to find specific informations about the mining hardware?
Ok, to offer a serious answer now....take a look at the reference designs released by Avalon.
https://bitcointalk.org/index.php?topic=200668.0I realize these aren't anything like BFL designss, but the basic board architecture won't be that different.
They will at least give you some insight in to the board layouts/layers, chip placement, power sources etc.
I'm not sure what format they were released in, I think it was Altium but perhaps someone has converted them to Eagle or some pcb design software that is easier to use for the average hobbyist.
Edit: I found the BFL reference design as well...
https://forums.butterflylabs.com/announcements/3295-bitforce-sc-pcb-schematics.htmlI haven't looked at it but this is what info they have on their site. (If it's from BFL it's sure to be disappointing.)