The problem isn't a lack of software to put on hardware, it's a lack of hardware that doesn't go out of its way to thwart attempts to install different software, either intentionally or as a side-effect of being optimized for cost.
As an example of the latter, I have a Monoprice-rebadged Tenda W301A ceiling-/wall-mount AP on my desk. It only has 2 MB of flash and 16 MB of RAM. It has a TTL serial port, but the lines are broken out to surface pads that aren't even grouped together on the PCB. (They're not labelled on the silkscreen, either.) The version of u-boot it ships with is stripped down to nothing, probably because of the limited flash space available. For ≤$5 more on the BOM, these problems could be fixed, and the device would be considerably more useful.
There are devices with more RAM (32MB or 64MB) and with USB port(s) where you can mount a flash drive / external disk and install anything (like Transmission, or even Samba) on it and use as a poor man's NAS. For example the TP-Link MR-3020 is pretty much hackable [0].
As an Engineer, I find the project completely fascinating. I believe that this project will (or already has) enhance Infrastructure/Datacenter Design and pave the way for the next generation of Software Defined Networking (SDN) Solutions. In some ways, the Open Compute Project is sort of flying under the radar. When you say Facebook to someone, they probably think of the Product. But if you take a look at what they're doing with this Project, and how it can impact underlying infrastructure, this is amazing. There are other things they're working on (not directly networking related) that are also amazing. Another project I find fascinating is the Prism Project (no, not the NSA one, the Facebook one). Right in line with Google's Spanner. Pretty cool stuff!
There's DD-WRT, and of course a ton of free routing software. But I think you mean open source hardware, which would be very difficult, considering the need for high-performing ethernet hardware and the like.
Yeah, you're not going to replace modern networking chips very easily.
If it's China you are worried about, perhaps work with a domestic chip producer like Broadcom. The chips might be fabbed in China, but it would be pretty difficult for China to sneak a "phone home" module into a GDSII drop.
This is the closest thing to what you're looking for that I've come across. Last I heard, there will be a kickstarter when it's ready. http://www.bunniestudios.com/blog/?p=3265
