While the bitcoin craze is on-going I've heard anecdotally of one retired GPU system being used to do CFD work, the reasoning was that people would pay $50 - $150 per hour for CFD analysis run time and that was more than the machine had been "earning" when it had been build for Bitcoin mining. That said, with an ASIC you're rather constrained in your choices.

But something in the same form factor as the mining ASIC might make this a pretty powerful engine for computing 'X' for some useful definition of X, post BitCoin exhaustion.