Some $US 50,000 is on offer. "Challenge" is perhaps a misnomer, as EOL is offering this money not as a prize at the end, but rather to fund one or more proposals (submitted by 22 May) that are accepted. So, it's essentially a grant competition (with a pleasingly minimal amount of administrivia). There is also a Computable Data Challenge community to discuss the challenge.
It's great to see EOL trying different strategies to engage with developers. Of the different challenges EOL is running this one is perhaps the most appealing to me, because one of my biggest complaints about EOL is that it's hard to envisage "doing science" with it. For example, we can download GenBank and cluster sequences into gene families, or grab data from GBIF and model species distributions, but what could we do with EOL? This challenge will be a chance to explore the extent to which EOL can support science, which I would argue will be a key part of its long term future.