I heard that 1024-core Parallellas would have high development costs and because of them not being suitable for mainstream, it is questionable whether they would be profitable. Now I had the idea that you could tweak your cores to optimize their performance for scrypt-based cryptocoin (Litecoin) mining. Bitcoin mining is not really worth optimizing because of low memory requirements which makes specialized bitcoin mining chips, which already start hitting the market, much faster and more efficient than any general-purpose processor like CPU,GPU or Parallella. But the scrypt algorithm has high (128kb I think) mem requirements which would make it quite suitable to the Epiphany chip.
While not as widespread as bitcoin, people mining Litecoin would certainly buy your devices in huge quantities if they provide better price/performance than existing GPUs. Don't forget to provide software for easy miner setup. Of course, the Epiphany always has to stay general-purpose, but stuff like a rotate instruction and maybe more memory per core would benefit other algorithms too. And miners just are a much bigger user group than the parallel algorithm geeks this was originally meant for.
I think it wouldn't be so hard to tweak your chips into becoming the most efficient for litecoin mining on the market. This would ensure development pays off and therefore maybe help shaping the future of parallel computing!