Not only does Broadcom refuse to sell chips to companies wanting to make Raspberry Pi compatible boards, but the PCB design is not public and the license on the closed-source binary blob required to boot the thing forbids use with non-Raspberry Pi boards.
You're far better off going with one of the Allwinner-based boards like the C.H.I.P if you intend to do this at some point in the future.
The closed design and closed-source kernel blob are troublesome. We need a completely open source board design similar to the Pi that manufacturers are free to produce without licensing. We could have an organization that does QA and vets individual manufacturers for quality and compliance/conformance with the board's design. The RPi Foundation's choice to remain so closed-source is a bit confusing and puzzling, considering their non-profit and educational mission and goal.
> We need a completely open source board design similar to the Pi that manufacturers are free to produce without licensing.
Unless I'm mistaken, the Beaglebone Black uses chips that are available for purchase from TI (and from which I think you can get datasheets, even as an individual), boots the mainline kernel, and provides CAD files for the board: http://elinux.org/Beagleboard:BeagleBoneBlack#Hardware_Files
> The RPi Foundation's choice to remain so closed-source is a bit confusing and puzzling, considering their non-profit and educational mission and goal.
Their founder and key personnel was/are employed by Broadcom. IIRC, essentially Broadcom thought of the Pi as a fun side project and were completely blown away by the demand.
The other problem is that people have written stuff, and loads of that, specifically for the Pi CPU/GPU - which makes a move away from BCM next to impossible:
- anything involving accelerated video isn't easily portable (e.g. omxplayer)
- anything that relies on a given special function of the CPU mapped to a specific GPIO pin might break with another CPU (e.g. extension boards)
- anything that relies on other rpi-specific hardware features (CSI, DSI) will be hard to port, but then again you don't really have a choice with non-usb/i2c camera or display modules...
Look into the Next Thing Co GR8 -- it's a vaguely similar SOC (the thing in the Chip Pro) but is (in theory - I haven't investigated) available in small quantities and with an accessible datasheet.
The latter. Their chips aren't sold through distributors, and they'll pretty much only give the time of day to high-volume OEMs. They stonewall companies that are big enough to get in-person visits from sales engineers from other major vendors (TI, Freescale, Xilinx). Raspberry Pi cofounder Eben Upton was a technical director at Broadcom, so he had inside connections.
They normally deal in massive quantities. Asking for a couple thousand units just isn't worth the effort. That's what makes the RPi Foundation unique -- Broadcom _does_ deal in small quantities for them in support of the mission.