https://www.kaggle.com/competitions
There's no reason XEL couldn't be used to solve Kaggle problems. But regardless of XEL, to come up with a solution someone has to code it in whatever language. I agree that this would be a great way to test out XEL, but unless someone steps up and helps out, it won't happen any time soon.
I don't mind stepping in. But I know nothing about the language. I could program some solutions using some of the already existing libraries out there in Python/Java/etc.
Remember it doesn't have to be the best solution, I'd be happy to see it being useful, not necessarily providing the best solution (for now).
ElasticPL is very much like C...just has 64,000 predefined ints (m[0] through m[63999]), 1,000 floats (f[0] through f[999]) and a different looping mechanism, but other than that if you can write a Kaggle solution in C, I'm sure we could get it ported over to ElasticPL pretty easily.